Abbreviation for Advanced Audio Codec. A compression and decompression algorithm and file format for audio data.


Abbreviation for Advanced Authoring Format. A cross-platform project exchange file format that you can use to import multiple audio tracks, inclusive of references to tracks, time positions, and volume automation.


A gradual increase in tempo (see tempo).

AD converter or ADC 

Short for analog-to-digital converter; a device that converts an analog signal to a digital signal.


Abbreviation for Alesis Digital Audio Tape. The ADAT is an eight track digital multitrack cassette recorder that uses an S-VHS video tape to record audio at 16 or 20 bit depth.

ADAT optical 

Optical interface for parallel transmission of eight audio channels via fiber-optic cable. It is a well-established standard for digital multi-channel interfaces.


Short for Audio Engineering Society/European Broadcasting Union. This association has a standard transmission format for professional stereo digital audio signals called AES/EBU. The format is similar to S/P-DIF, but uses balanced line drivers at a higher voltage. Depending on the type of devices involved, AES/EBU and S/P-DIF coaxial interfaces can communicate directly.


MIDI data-type generated by pressure on keys after they have been struck. There are two types:  Channel aftertouch, the value of which is measured by a full length keyboard sensor. It affects all played notes. Polyphonic aftertouch (rare) is individually measured and transmitted for each key. Aftertouch is also known as key pressure or pressure sensitivity.


Abbreviation for Audio Interchange File Format. A cross-platform file format supported by a large number of digital audio and video editing applications. AIFF audio can use a variety of bit depths, most commonly 16 and 24 bit.


Abbreviation for Apple Lossless Audio Codec, an encoding/decoding algorithm that delivers lossless audio compression.


A pointer to a MIDI region in the Arrange area. An alias does not contain any data. It simply points to the data of the original MIDI region. You can create an alias by Shift-Option-dragging the original MIDI region to a new location. An alias cannot be edited directly. Any change to the original region will be reflected in the alias.


A digital artifact that occurs when the sample material contains frequencies higher than one-half of the sample rate.

allpass filter 

A filter that allows all frequencies to pass, providing only phase shift or phase delay without appreciably changing the amplitude characteristic.


Device that increases the level of a signal.


This term is used to describe the amount of a signal. If you have an audio signal, amplitude refers to the volume of the sound, measured in decibels (dB).

amplitude peak 

The loudest point of an audio signal.

analog signal 

A description of data that consists of an endlessly varying voltage level that represents audio information. Analog signals must be digitized, or captured, for use in Logic Pro. Compare with digital.

anchor point 

The start point of the audio file that an audio region is based on. Also see Sample Editor.

Apple Loops 

An audio file format, commonly used for recurring rhythmic musical elements or elements suitable for repetition. Apple Loops contain tags and transients that are used by Logic Pro for time stretching and pitch shifting tasks. These tags also allow you to quickly locate files by instrument, genre, or mood in the Loop Browser.

Arrange area 

The primary working space of Logic Pro. It is used to record, edit, move, and arrange the audio and MIDI regions of a project. Also used for automation recording and playback.

Arrange window 

The primary working window of the application. It also shows the Arrange area (see above), and can incorporate all other working areas and editors.


Acronym for American Standard Code for Information Interchange. Standard computer character set, allowing computers to deal with text characters. When you type ASCII characters from the keyboard, the computer interprets them as binary so they can be read, manipulated, stored, and retrieved. Also see scan code.


Start phase of a sonic event. Also part of an envelope. See envelope.


The act of lowering the level of an audio signal (see boosting and cutting).

Audio Bin 

Window (or tab in the Media area of the Arrange window) used for project audio file and region management and conversion tasks. See Media area.

audio channel strip 

Channel strip in the Mixer, used as a target for audio tracks in the Arrange area. All data on the audio track is automatically routed to the audio channel strip that was assigned in the Arrange track list.

audio file 

Any digital recording of sound, stored on your hard disk. You can store audio files in the AIFF, WAV, Sound Designer II (SDII), and CAF formats in Logic Pro. All recorded and bounced WAV files are in Broadcast Wave format.

audio interface 

Device used to get sound into and out of your computer. An audio interface converts digital audio data, sent from your computer, into analog signals that speakers can broadcast. In the other direction, an audio interface converts analog signals (such as a vocal performance) into digital audio data that can be understood by your computer.

Audio MIDI Setup (AMS) 

The Audio MIDI Setup (AMS) utility is used to configure the audio and MIDI input and output devices connected to your computer. Logic Pro uses the settings defined in the Audio MIDI Setup utility, which can be found in the Applications/Utilities folder.

audio region 

Chosen area of an audio file that can be placed on audio tracks in the Arrange area, just like a MIDI region can be placed on MIDI tracks. Audio regions are aliases (or pointers) to portions of audio files. They can be as short as a single sample, or the full length of the underlying audio file. Logic Pro allows you to edit audio regions without affecting the original audio file. Also see region and MIDI region.

audio track 

A track in the Arrange window that is used for playback, recording, and editing of audio regions. It is routed to an audio channel in the Mixer.

Audio Units (AU) 

Audio Units is the standard Mac OS X format for real-time plug-ins. It can be used for audio effects, software instruments, and Generators. The Audio Units format is incorporated into the operating system, and installed Audio Units plug-ins can be simultaneously accessed by all applicable programs. Logic Pro supports all Audio Units format plug-ins.

Auto Track Zoom 

Function in the View menu that automatically enlarges the currently selected track.


Automation is the ability to record, edit, and play back the movements of all knobs, controls, and buttons, including volume faders, pan, EQ, and aux send controls, plus most effect and instrument plug-in parameters.

Autopunch button 

Button (with the up/down arrows) in the Transport bar, used to activate the Autopunch function.

Autopunch function 

Autopunch refers to an automatic entry and exit of record mode at predefined positions. Autopunch mode is most commonly used to re-record a badly played section of an otherwise flawless recording. The advantage is that you can concentrate on playing, not the mechanics of driving Logic Pro. Autopunch is activated by clicking the Autopunch button in the Transport bar.

aux channel (strip) 

Aux channels are found in the Mixer (and to the left of the Arrange window), and can be used as send/returns (buses) and sub-group controls.

Balance control 

Rotary knob directly above the Level fader of stereo channels. It controls the relative level of the left and right signals at their outputs.

band rejection filter 

This filter cuts the frequency band centered around the cutoff frequency, while allowing the frequencies that lie further away to pass. The mid-range frequencies will become softer and the lows and highs remain unchanged.

bandpass filter 

This filter only allows the frequency band centered around the cutoff frequency to pass, while frequencies that lie further away (the lows and highs) are filtered out. A sound that contains a lot of mid-range frequencies is the result. Also see filter.


In musical notation, a bar is a measure that contains a specified number of beats, and establishes the rhythmic structure of a musical piece.

Bar ruler 

Ruler found at the top of the Arrange window and the Piano Roll Editor, Hyper Editor, and Score Editor. It displays musical time units, including bars, measures, beats, and beat divisions. It is used to set and display the project position, the cycle and autopunch locators. Also see playhead, Cycle function, and Autopunch function.


A musical instrument. The term also refers to low-frequency sounds or components within a sound. See frequency.


A musical time interval. Usually a quarter note.

Beat Mapping track 

Global track used to analyze audio or MIDI regions, and create tempo events based on note or transient events in these regions. This allows you to more easily synchronize existing free recordings (those made without a metronome click) in other projects.

beats per minute 

See bpm.

Bezier curve 

A curve created from a line that contains two points. These points affect the line, allowing it to be pulled into a curve. In a computer application, Bezier curves are created by moving handles at these two points, thus adjusting the curve shape. Named after Pierre Bezier, who discovered the mathematical formula for these curves. In Logic Pro, Bezier curves are used to adjust automation curves, for example.

binaural hearing 

A description of the way human beings process audio positioning information, allowing the direction of a signal source to be recognized (in front, behind, above, below, and to the left or right of the listening position).

binaural panning 

A process that emulates binaural hearing.

bit depth 

The number of bits used by a digital recording or digital device. The number of bits in each sample determines the (theoretical) maximum dynamic range of the audio data, regardless of sample rate.

bit rate 

Bit rate, when talking about MP3 files, refers to the transfer bit rate at which the files are encoded. Conversationally, the term is more often used to describe the relative quality of the file, with lower bit rates resulting in less defined audio.

bit resolution 

Alternative term for bit depth. See bit depth and sample rate entries.

blue noise 

Highpass-filtered white noise, which sounds like tape hiss.


The act of raising an audio level (see cutting).


To process MIDI or audio regions with any applied effects, such as delay or compression, and combining them into one audio file. In Logic Pro, you can choose between real-time and offline bouncing. Offline bouncing is faster, but doesn’t allow you to apply live automation or record real-time audio input. You may also bounce to several files when performing a Surround bounce. See surround.

Bounce button 

You can bounce the output of any output channel to an audio file by clicking the Bounce button. Also see bounce.


Abbreviation for beats per minute, a measure of the tempo of musical piece. As an example:  120 bpm means that in one minute, there will be 120 musical beats (quarter notes).

Broadcast Wave 

See Wav, Wave.


A tab in the Media area of the Arrange window used to browse, select, and manage all media types supported by Logic Pro. Also see Media area.


Busses are used to send audio to aux channel strips for processing or submixing tasks.

bus channel strip 

The bus channel type is primarily included for backward compatibility with older Logic Pro versions. The bus channel strip functions of earlier versions are performed with aux channel strips in Logic Pro 8.


To deactivate a plug-in. Bypassed plug-ins do not drain system resources. In Logic Pro you can bypass a plug-in by either clicking its Bypass button in the plug-in window or by Option-clicking the appropriate plug-in slot of a channel strip.


In Logic Pro, the term is used to describe the virtual cables that represent a MIDI connection between Environment objects.


Abbreviation for Core Audio Format. This file format can be used as a container for compressed or uncompressed audio files of (almost) any size, sample rate, or bit depth. The CAF file format can handle audio recordings of around 3 hours in length (at a 44.1 kHz sample rate—shorter at higher sample rates).

Camera tool 

The Camera tool is used to select, and export, sections of the Score Editor display as PDF files.

Caps Lock Keyboard 

Logic Pro function that allows the use of the computer keyboard as a real-time MIDI keyboard. It is primarily intended for use while travelling with a portable Macintosh.


In FM synthesis, the carrier is the equivalent of an analog synthesizer oscillator that is producing a sine wave. The carrier frequency is modulated by the modulator.

Catch button 

The button at the top-left corner of most windows featuring the running man icon. Activate this button to enable horizontal scrolling during playback. This ensures that the area of the project that surrounds the current playhead position is always visible.

CD Audio 

Short for Compact Disc-Audio; a standard for stereo music CDs:  44.1 kHz sampling rate and 16-bit depth.


A tuning division of a semitone. There are one hundred cents in a semitone. Many of the Logic Pro software instruments contain a Fine parameter that allows sounds to be tuned in cent steps.

channel strip 

A channel strip is a virtual representation of a channel strip on a mixing console. Each channel strip contains a number of similar controls, which can include some or all of the following:  a Mute button, Level fader, Pan/Balance control, Input slot, Output slot, Send slots, Insert slots, Format button. The channel strips shown to the left of the Arrange window, and in the Mixer window, are used to process audio or MIDI information that is routed from arrange tracks.

channel strip setting 

Logic Pro allows the routing of a channel strip, including all inserted effects or instruments (plus their settings) to be saved and recalled. This simplifies the task of re-creating complex serial effect routings between channels or projects.


A small box. You click a checkbox to select or deselect (or turn on/off) an option.

Chord track 

One of the global tracks. Contains chord symbols that can be derived from MIDI regions or created with the mouse. These chord symbols may also be inserted into the score. The root note of the chords determines the transposition (pitch shifting) of all Apple Loops, and can also affect the playback of MIDI regions.

chorus effect 

Effect achieved by layering two identical sounds with a delay, and slightly modulating the delay time of one, or both, of the sounds. This makes the audio signal routed through the effect sound thicker and richer, giving the illusion of multiple voices.


Metronome, or metronome sound.


The Clipboard is an invisible area of memory, into which you cut or copy selected data, using the Edit menu. Data stored in the Clipboard can be pasted to different positions. In Logic Pro, the Clipboard can be used to exchange data within a single project or between projects.

clipping (in digital recording) 

Feeding too much signal through a channel strip, thereby exceeding the limit of what can be accurately reproduced, results in a distorted sound known as clipping. Logic Pro audio channel strips feature a clip detector, which indicates signal level peaks above 0 dB.


Electrical synchronization impulse, transmitted every 1/96 note. Was used in older drum machines before the advent of MIDI. (MIDI Clock is a modern implementation of simple clock signals. It runs at 24 ppqn—pulses per quarter note—or 96 pulses per note.)

cloned audio region 

A cloned audio region is a pointer to the original region. Whenever you adjust the start or end points of any of these cloned regions, all other cloned regions will also be adjusted in the same way.

comb filter effect 

A short delay of feedback that emphasizes specific harmonics in a signal is generally termed a comb filter. The name is derived from the appearance of a frequency spectrum graphic, which resembles the teeth of a comb.


A process where multiple recording takes are combined into a single perfect take. See takes.


An effect that restricts the dynamic range of an audio signal (also see expander).

Content Link mode 

The chain link button found at the top-left corner of most Logic Pro windows features three modes. Content Link mode is useful for situations where multiple MIDI regions are horizontally aligned along a single track, and you are viewing the MIDI region contents in the Piano Roll Editor, for example. In this scenario, the Piano Roll Editor will only show the contents of the selected MIDI region. Should you wish to view the contents of each MIDI region (selected or not) in the Piano Roll Editor as the project plays, you will need to activate Content Catch mode.


MIDI data type. As examples:  sliders, pedals, or standard parameters like volume and panning. The type of command is encoded in the first data byte, the value being sent or received is encoded in the second data byte.

control surface 

A hardware device that communicates with Logic Pro via MIDI (or USB, FireWire, or via a networking connection). It can be used to write automation data and control Logic Pro parameters, such as mixing levels and panning, effects and instruments, plus transport and navigation functions, amongst others.

Controls view 

All Logic Pro plug-ins (and Audio Units) offer a non-graphical alternative to the Editor views of effect and instrument parameters. The Controls view is accessed via the Controls item in the plug-in header’s View menu at the top of each plug-in window. This view is provided to allow access to additional parameters and to use less onscreen space.

Core Audio 

Standardized audio driver system for all Macintosh computers running Mac OS X version 10.2 or later. Core Audio is an integral part of Mac OS X, allowing access to all audio interfaces that are Core Audio compatible. Logic Pro is compatible with any audio hardware that offers Core Audio drivers/support.

Core MIDI 

Standardized MIDI driver system for all Macintosh computers running Mac OS X version 10.2 or later. Core MIDI is an integral part of Mac OS X, allowing the connection of all MIDI devices that are Core MIDI compatible. Logic Pro is compatible with any MIDI hardware that offers Core Audio drivers/support.


Beats heard prior to the start of a recording (or playback).


Monitoring (hearing playback) while fast-forwarding or rewinding.

cutoff frequency 

Frequency at which the audio signal passing through a low or highpass filter is attenuated by 3 dB.


The act of reducing a level, or frequency, when using EQ or other filters. Also used to describe physically dividing and removing sections of files, regions, and so on (see boosting and attenuate).

Cycle function 

A function in Logic Pro that constantly repeats the area between the locator positions. To turn on Cycle mode, click the Cycle button in the Transport bar. The Cycle function is useful for composing a part of a project or editing events, as examples. The cycle area is shown as a green stripe in the top part of the Bar ruler.

DA converter or DAC 

Short for digital/analog converter; a device that changes an analog signal into a digital signal.

data bytes 

These define the content of a MIDI message. The first data byte represents the note, or controller number; and the second the velocity, or controller value.


Acronym for Digital Audio Workstation. A computer used for recording, mixing, and producing audio files.


Abbreviation for decibels, a unit of measurement that describes the relationships of voltage levels, intensity, or power, particularly in audio systems.

DC offset 

An error that can result in direct current (DC) being layered over the audio signal, resulting in a vertical shift in the waveform position shown in the Sample Editor.


An envelope parameter that determines the time it takes for a signal to fall from the maximum attack level to the sustain level. See envelope.


A signal processor that removes hissing or sibilance in audio signals.


The preset parameter value.


In the Environment, an object that can create a series of repeats. In the Arrange window, a region parameter that can delay or advance a selected region by a given number of milliseconds. Delay is also an effect process that delays the incoming audio signal, resulting in subtle chorusing effects through to endless repeats of the signal.


Destructive audio processing means that the actual data of an audio file is changed, as opposed to just editing peripheral or playback parameters.

Devices pane 

In Logic Pro, the Logic Pro > Preferences > Audio > Devices pane is used to select and configure your audio hardware devices. In essence, you are altering the driver configuration of your devices when using the Devices pane parameters. Also see driver.


An abbreviation for Digital Full Scale. Sometimes expressed as 0 dB DFS. This (zero dB—as shown on the Logic Pro channel strip level meters) is the maximum theoretical level that a digital signal can reach before clipping and other types of distortion may be introduced.


A window containing a query or message. You must interact with it (by clicking a button) before you can continue.


A description of data that is stored or transmitted as a sequence of ones and zeros. Most commonly, refers to binary data represented by electronic or electromagnetic signals. All files used in Logic Pro are digital. Also see analog for comparison.

Digital Full Scale 

See DFS.

disclosure triangle 

A small triangle you click to show or hide details in the user interface.


The effect that occurs when the limit of what can be accurately reproduced in a digital signal is surpassed, resulting in a sharp, crackling sound.

division value 

Adjustable value (shown in notes) for the grid used in displays and operations. Third number displayed in the Transport bar’s Position display. The division value is set in the Transport bar, below the time signature.

drag and drop 

Grabbing objects with the mouse, moving them, and releasing the mouse button.

drag editing 

A Take Folder Editing mode where you use the mouse to cut, drag, and move take folder and take region elements. See quick swipe comping.

Drag pop-up menu 

A pop-up menu found in the local menu of linear editing windows. It determines the behavior of regions or events when dragged to an overlapping position.


Drivers are software programs that enable various pieces of hardware and software to be recognized by computer applications. If the proper driver is not correctly installed for your audio hardware, your computer may not recognize or work properly with it. See Devices tab.

DSP (digital signal processing) 

In Logic Pro, the mathematical processing of digital information to modify a signal. An example is the Insert slot of channel strips, which assigns DSP effects such as dynamic compression and delay to a channel signal. Even simple operations such as changing volume and pan are DSP calculations.

dynamic range 

The dynamic range is the difference in level between the highest signal peak that can be reproduced by an audio system (or device in the system) and the amplitude of the highest spectral component of the noise floor. Put another way, the dynamic range is the difference between the loudest and softest signals that the system can reproduce. It is measured in decibels (dB). See dB.


Refers to changes in volume, or other aspects of a piece of music, over time.


Window for editing MIDI or audio data. Logic Pro offers the Hyper, Piano Roll, Event List, and Score editors for MIDI event data, and the Sample Editor for audio data. The Event List can also be used for region editing and positioning tasks.

Editor view 

Almost all Logic Pro plug-ins (and Audio Units) offer a graphical view of effect and instrument parameters. The Editor view is the default, but can be accessed via the Editor item in the View menu at the top of each plug-in window, should the Controls view be visible.


A type of software algorithm that alters the sound of an audio signal in a variety of ways. Logic Pro includes a set of EQ, dynamics, time-based, modulation, and distortion effects in the Logic Pro native and Audio Units plug-in formats.


The envelope graphically represents the variation that a sound exhibits over time. An envelope, used as a controlling device, basically determines how a sound starts, continues, and ends. Synthesizer envelopes usually consist of attack, decay, sustain, and release phases.


The Logic Pro Environment graphically reflects the relationships between hardware devices outside your computer and virtual devices within your computer. Beyond basic input and output handling, the Environment can be used to process MIDI data in real time, and can even be used to create processing machines, such as virtual rhythm generators and step sequencers or complex synthesizer editors.

Environment layer 

A page in the Environment, used to organize objects. Objects of the same type (MIDI objects, for example) are generally placed on the same layer, making usage easier.

Environment Mixer 

See Mixer layer.


Shortened form of equalizer. Equalizers are used to boost or cut frequencies in an audio signal. There are several types of EQ available in Logic Pro.


See EQ.


A tool used for deleting items. Click a selected item to delete it. All other currently selected items are also deleted.


Individual MIDI command, such as a note on command. Continuous controller movements (modulation wheel, for example) produce a quick succession of individual events—each with an absolute value.

event definition 

Parameters used to define the event type displayed in the lanes of the Hyper Editor (also see hyper set).

Event List 

A list that shows all events or regions in a project. It allows you to directly manipulate events and regions in a precise, numerical way. It also allows you to add different types of events.


An effect process that increases the dynamic range of an audio signal. It is the antithesis of the compression effect (see compressor).


To create a version of a file, such as a Logic Pro project, in a different format that can be distributed and used by other applications.

Fade tool 

Tool in the Arrange area, used to create a cross-fade.

Filter button 

Buttons in the Event List and Mixer that allow you to hide or show specific event types or channel strip types.

filter effect 

Filters are effects designed to reduce the energy of a specific frequency within a signal. The names of the individual filters illustrate their function. As an example:  A lowpass filter allows frequencies that are lower than the cutoff frequency to pass (see cutoff frequency).

filter slope 

The filter slope is the steepness, or severity, of filter attenuation (level reduction). As examples, a filter slope of 6 dB per octave would sound much softer than a filter slope of 12 dB per octave.

Finger tool 

Tool (as used in the Piano Roll Editor, for example) that looks like a hand with an extended index finger. This tool allows you to manipulate the length of events or perform other operations in other areas of the program.


Apple trademarked name for the IEEE 1394 standard. A fast and versatile serial interface, often used to connect audio interfaces, and audio processing units to computers. FireWire is well suited to applications that move large amounts of data, and can be used to connect hard disks, scanners, and other kinds of computer peripherals. There are two versions of FireWire:  FireWire 400 and FireWire 800. The latter is a faster variant, which uses a different connector type. Use of FireWire 400 devices on a FireWire 800 port is possible with suitable cabling, but it effectively halves the bandwidth to all devices on the port (also see M-LAN).


The flanger effect is similar to the chorus effect, where a slightly delayed signal (which is shorter than that of the chorus) is fed back into the delay line input. Flanging makes a sound thicker, and slightly out of phase.

flex marker 

A marker that you drag in order to alter the timing of audio material.

flex mode 

A track-based setting that determines how the timing of your audio will be altered.

flex time editing 

A process that allows you to edit the timing of single or multiple audio regions.

Flex tool 

A tool that allows you quick access to the basic flex time editing functionality, without having to turn on Flex view in the Arrange area. See Flex view.

Flex view 

An Arrange area view that allows you to edit the timing of audio material.

float window 

See window type.


A folder is a container for regions in the Arrange area. It can contain other folders or regions, much like a folder in the Finder can contain other folders or files. You can imagine a folder as a project within a project. The inside of a folder looks just like the Arrange area and track list in a project.

Format button 

Button on audio channel strips (below the level meter), used to indicate the input format of the channel strip. Click-hold this button to access the format menu.


Unit of time. A second in the SMPTE standard is divided into frames that correspond to a single still image in a video file or on video tape.

Freeze function 

The Freeze function performs individual offline bounce processes for each frozen track, saving almost 100% of the processing power used for software instruments and effect plug-ins. All plug-ins of a track (including software instrument plug-ins, if applicable, along with all related automation data) are rendered into a freeze file.


The number of times a sound signal vibrates each second, measured in cycles per second, or Hertz (Hz).

global tracks 

Global tracks are available at the top of all linear editing windows. They allow you to view, create, and edit markers, tempo events, and key changes, plus beat mapping and other operations.

Glue tool 

This tool can be used to merge regions or events by simply clicking on two (or more) of them.


Abbreviation for General MIDI. A standard for MIDI sound modules that specifies a uniform set of instrument sounds on the 128 program numbers, a standardized key assignment for drum and percussion sounds on MIDI channel 10, 16-part multi-timbral performance and at least 24 voice polyphony. The GM specification is designed to ensure compatibility between MIDI devices. A musical sequence generated by a GM instrument should play correctly on any other GM synthesizer or sound module.

grab (an object) 

Positioning the mouse cursor over an object, then pressing and holding the mouse button down.


The Logic Pro grid is represented by vertical lines that are used to indicate the positions of measures, beats, and sub-beats in various editors.


Extended GM standard developed by Roland Inc.

Hand tool 

A tool used to move regions in the Arrange area or events in editors, or plug-ins between Insert slots in the Mixer. It automatically appears when the mouse cursor is placed over a region or event while the Pointer tool is selected.


A specified range (safety margin, measured in decibels) between the actual audio level and the maximum permitted level (0dBfs) that allows for unexpected signal peaks.

help tag 

A small text window that appears when the mouse cursor is placed over an interface element. It indicates the name or value of the element. When editing operations such as moving or cutting a region are performed, a larger help tag will display the current (and starting) position of the region or function—in real time.

hierarchical menu 

Structured menus that open cascading submenus when an individual entry is chosen at a higher level.

Hierarchy button 

In the top-left corner of many Logic Pro windows, you will find a button featuring an upward pointing, right-angled arrow. Clicking this Hierarchy button takes you to the next, higher display level (one level up, in other words). As an example, if you are looking at the events of a MIDI region inside a folder, clicking the Hierarchy button will switch the display to a view of the MIDI region in the parent folder. A further click will take you up to display the folder itself.

high cut filter 

A high cut filter is essentially a lowpass filter that offers no slope or resonance controls. As the name suggests, it attenuates frequencies above the cutoff.

highpass filter 

A highpass filter allows frequencies above the cutoff frequency to pass. A highpass filter that offers no slope or resonance controls is generally known as a low cut filter.

Hyper Draw function 

This function allows you to record, manually create, and edit controller data graphically. Hyper Draw data appears as a set of points (or nodes), which are connected by lines. Hyper Draw can be used in the Arrange area and MIDI editors.

Hyper Editor 

Graphical editor that can be used to create or edit MIDI note and controller data. The Hyper Editor is ideal for drawing drum parts and creating crescendi, amongst other tasks. See entry below and also see event definition.

hyper set 

All simultaneously displayed event definitions in the Hyper Editor are collectively referred to as a hyper set. Also see event definition.


Small graphic symbol. In Logic Pro, an icon may be assigned to each track.


The process of bringing files of various types into a Logic Pro project. Imported files can be created in another application, captured from another device, or taken from another Logic Pro project.

In button 

Button used to activate Step Input mode in the editors. Also see Step Input function.

input channel strip 

Channel strip type in the Environment Mixer layer that is included for backward compatibility with projects created in older Logic Pro versions. An input channel strip represents the physical inputs of your audio interface and directs input from your audio interface into Logic Pro. In general, you will not need to access this channel strip type in Logic Pro.

input monitoring 

This function allows you to hear incoming audio, when audio tracks are playing, record-enabled, or recording. Simply click the Input Monitoring button on Arrange audio tracks to enable or disable input monitoring.

Insert slot 

A panel on Logic Pro channel strips where you can patch in (insert) an effect plug-in.


Area at the left edge of the Arrange window and editors, containing the Parameter boxes and channel strips (Arrange) of the selected track. The Inspector area updates to reflect the parameters relevant to the window with key focus. Also see Parameter box.

instrument channel strip 

Logic Pro supports the use of software-based instruments. Software instrument plug-ins are inserted into the Instrument slot of instrument channel strips. Software instrument recording takes place on instrument tracks in the Arrange area. Playback of these tracks is routed via the instrument channel strip shown in the Mixer (or to the left of the Arrange window).

instrument object 

An object in the Logic Pro Environment designed to communicate with a single-channel MIDI device. An instrument object represents a physical or virtual device that handles MIDI information. Also see multi-instrument object.


1) A hardware component such as a MIDI or audio device that allows Logic Pro to interface (connect) with the outside world. You need an audio or MIDI interface to get sound or MIDI into and out of your computer. Also see audio interface. 2) A term that is used to describe graphical elements within Logic Pro that you can interact with. An example would be the Arrange area, where graphical interface elements such as regions are interacted with to create a project, within the overall Logic Pro interface.

interleaved audio file 

Logic Pro typically handles multi-channel (stereo or surround) audio files as interleaved. Edits to interleaved files affect both (or all, if surround) channels equally. Also see split channel audio files.


The scale used in a piece of music, centered around a specific pitch. The specified pitch is called the root of the key. Can also refer to a black or white key on a musical (MIDI) keyboard.

key command 

Function that can be executed by pressing a specific key (or key combination) on your computer keyboard or MIDI controller.

Key Commands window 

The Key Commands window is used for the assignment of key commands to computer keys or to MIDI messages.

key focus 

The selected, active window, is said to have key focus in Logic Pro. Many key commands will only function when a window has key focus. The Inspector also updates to reflect the parameters of a window with key focus.


You may notice a delay between playing your keyboard and hearing the sound. This is a form of latency. A variety of factors contribute to latency, including the audio interface in use, audio and MIDI drivers. One factor under your control, however, is the I/O buffer size, which is set in the Devices preferences.


Method of musical performance that smoothly connects one note to the next.

level meter 

A meter that monitors audio input or output levels to or from your computer. You use the level meters in Logic Pro when recording, arranging, and editing audio files, and when creating a mix.


Abbreviation for Low Frequency Oscillator. An oscillator that delivers modulation signals below the audio frequency range—in the bandwidth that falls between 0.1 and 20 Hz, and sometimes as high as 50 Hz or 400 Hz.


Window (or tab in the Media area of the Arrange window) used to handle all settings files for channel strips, effects, and instruments.

Link button 

Button in the top-left corner of most Logic Pro windows that features the chain link icon. It controls the linking between different windows.

Lists area 

Area in the Arrange window, providing four independent tabs that show a listing of the following types of data:  events, regions, markers, tempo changes, and time/key signatures.

local menu bar 

Menu in a window that only contains functions that are relevant to that particular window.

Local Off mode 

Operating mode on a MIDI keyboard where the keyboard does not directly play its own integrated sound generator. This is useful when using it as a master keyboard for Logic Pro.


Lower two sets of numbers, displayed to the right of the position indicators in the Transport bar. The number on top is the left locator; the number below is the right locator. The left and right locators define the cycle time-range, useful for cycle or skip playback operations and cycle recording. The locators are also used to define the editing area for certain functions.


An audio file that contains recurring rhythmic musical elements, or elements suitable for repetition. Logic Pro supports Apple Loops, amongst other file formats.

Loop Browser 

A tab in the Media area of the Arrange window used to access and manage Apple Loops and ReCycle files.

Loop function 

The Loop region parameter in Logic Pro that creates loop repeats for an audio or MIDI region. These repetitions will continue until the project end point is reached, or another region or folder (whichever comes first) is encountered on the same track in the Arrange area.

low cut filter 

A low cut filter is essentially a highpass filter that offers no slope or resonance controls. It attenuates all frequencies below the defined cutoff.

lowpass filter 

The lowpass filter defines the maximum frequency that can pass through without being affected, thus controlling the brightness of the sound. Every signal above this frequency will be cut. The higher the cutoff frequency, the higher the frequencies that can pass through. A lowpass filter that offers no slope or resonance controls is a high cut filter.

main menu bar 

The bar at the top of the screen, offering global functions such as opening, saving, exporting, or importing projects. It does not offer access to local window functions. It does, however, contain an Edit menu—with commands that apply to the window with key focus.


A marker is an indicator, or bookmark, that is tied to a specific time position in a project. It can contain text that act as notes for different versions of a project, for example. Markers can also be used for a number of selection and navigation tasks.

Marker List 

Window (or tab in the Lists area of the Arrange window) that shows an alphanumeric listing of all marker events. It also includes a Marker Text area that allows you to add text information (notes) to particular marker events.

marker text 

Text information (notes) attached to particular marker events. Added in the Marker Text window or Marker Text area of the Marker List.

Marker track 

One of the global tracks, used for the creation, editing, and display of marker events.

Marquee tool 

Crosshair-shaped tool in the Arrange Tool menu, used to select and edit parts of audio and MIDI regions.

master channel strip 

Channel strip in the Mixer that acts as a separate attenuator stage, changing the gain of all output channel strips without affecting the level relationships between them.

Media area 

Area shown at the right-hand side of the Arrange window when the Media button is clicked in the Arrange toolbar. Contains the Bin, Loops, Library, and Browser tabs, providing access to all media types supported by Logic Pro.


Mix, or combine, two or more MIDI events or regions into a single event or region.


Metadata is additional descriptive information that is stored in the file header of a number of file types (AAF, for example). It is used to reference external media, to simplify searches, and more.


A device that produces a sound that taps out the beat. In Logic Pro, it can be configured in the Metronome project settings.


Abbreviation for Musical Instrument Digital Interface. Standardized, asynchronous, serial, event-oriented hardware and software interface for electronic musical instruments. MIDI is an industry standard that allows devices such as synthesizers and computers to communicate with each other. It controls the pitch, length, and volume of a musical note event, among other characteristics.

MIDI channel 

A MIDI channel is a “tube” for MIDI data, which flows through MIDI ports. Up to 16 separate MIDI channels can pass through a port simultaneously. Tracks recorded in Logic Pro can be directed to different tubes (channels), which can contain different information, and play back through different sounds, assigned to each channel. As examples, channel 1:  piano, channel 2:  bass, channel 3:  strings, and so on. This assumes that the receiving devices are capable of receiving data on more than one channel, and that they are capable of playing back different sounds simultaneously (see multi-timbral).

MIDI Clock 

Short MIDI message for clock signals. It is used to provide a timing pulse between MIDI devices. It is accurate to 24 ppqn (pulses per quarter note), although some devices interpolate these pulse values, resulting in a more precise clock signal if each device is capable of interpreting this additional information correctly. Also see SPP.

MIDI message 

A message transmitted via MIDI that consists of one status byte and none, one, two, or many data bytes (with system exclusive commands). See event.

MIDI Multi mode 

Multi-timbral operating mode on a MIDI sound module where different sounds can be controlled (polyphonically) on different MIDI channels. A multi mode sound module behaves like several polyphonic sound modules. General MIDI describes a 16-part multi mode (the ability to control 16 different parts individually). Most modern sound generators support multi mode. In Logic Pro, multi mode sound modules are addressed via multi-instrument objects. This MIDI mode and multi mode sound modules are generally referred to as multi-timbral (see multi-timbral).

MIDI region 

Data container for MIDI events, shown in the Arrange area as a named horizontal beam.

MIDI Time Code (MTC) 

Translation of a SMPTE time code signal into a MIDI standard time code signal. MTC is used to synchronize Logic Pro with MIDI devices, other sequencers, video and audio tape or hard disk machines that support MIDI Time Code. MTC determines absolute time positions and supports start, stop, and continue messages.


A term commonly used to describe either bouncing (see bounce) or merging of tracks (see merge).


The Mixer window displays all (or the desired) track, instrument, and MIDI channel strips. These channels allow you to control all aspects of track output and processing, including level, panning, effect and instrument processing, routing, and more.

Mixer layer 

An Environment layer that shows all channel strips in a project (except MIDI channel strips). In general, you will not need to access this Environment layer as all mixing duties can be performed in the Mixer window.


The process of shaping the overall sound of a project by adjusting the volume levels, pan positions, adding EQ and other effects, and using automation to dynamically alter these and other aspects.


A Yamaha-designed variant of the FireWire interface. It enables Yamaha digital mixers and other devices to be directly connected to a Macintosh FireWire port (see FireWire).

modifier key 

Computer keyboard keys used in conjunction with alphabetical keys to change functionality. Modifier keys include Control, Shift, Option, and Command.


Generally, a slight, continuously varying change. Many Logic Pro effects and synthesizers contain modulators.

modulation amount 

The strength, or intensity, of modulation.

modulation matrix 

The EXS24 mkII (and some other Logic Pro instruments) contains a grid that allows you to vary a number of target parameters, such as pitch, with a number of modulators (modulation sources). This grid is referred to as the modulation matrix in the EXS24 mkII.

modulation path 

A modulation path determines which target parameter will be affected by a specific modulator (modulation source).

modulation wheel 

A MIDI controller found on most MIDI keyboards.


Short for monophonic sound reproduction. The process of mixing audio channels into a single track, using equal amounts of the left and right audio channel signals. Compare with stereo.


See video.


Abbreviation for MPEG-2 Audio Layer 3. A compressed audio file format, frequently used to distribute audio files over the Internet.


See MIDI Time Code.

multi-instrument object 

An object in the Logic Pro Environment that represents a multi-timbral hardware or software device that reacts to MIDI. The multi-instrument object is essentially 16 instrument objects rolled into a single package. Each of these, called sub-channels, has a fixed MIDI channel. All sub-channels share the same MIDI port. All other parameters can be set individually. The purpose of the multi-instrument object is to address multi-channel MIDI devices, which can receive MIDI data (and play different sounds) on separate MIDI channels.


This term describes an instrument or other device that can play several different sounds at the same time, using multiple MIDI channels. See MIDI Multi mode.

Multi Trigger mode 

This term is associated with synthesizers such as the ES1. In this mode, a synthesizer envelope is usually retriggered by each incoming note event.


Turn off the audio output of a channel or track. You can mute a track or channel by clicking the Mute button in the track list or at the bottom of the channel strip.

Mute tool 

This tool allows you to stop a region or events from playing, by clicking it or them.


Native refers to host-based processing of effects and software instruments in Logic Pro. The computer processor natively calculates the effects and instruments. Native also refers to the internal Logic Pro plug-in format, which differs from the Audio Units format. Logic Pro native plug-ins only work in Logic Pro.


Positions in Hyper Draw and automation tracks that mark the beginning or end of data manipulation. Occasionally referred to as (automation) points.


This function applies the current Parameter box settings to the selected MIDI events (by altering the actual events themselves), and clears existing parameter settings. When it comes to audio, a different Normalize function raises the volume of a recorded audio file to the maximum digital level, without altering the dynamic content.

notch filter 

This filter type cuts the frequency band directly surrounding the cutoff frequency, allowing all other frequencies to pass.

note attributes 

Describes functions found in the Attributes menu of the Score Editor. These determine aspects such as the stem direction, color, enharmonic position, and further options for the display (and printing) of note events.

note number 

Pitch of a MIDI note, controlled by the first data byte of a MIDI note event.


The term is used to refer to the graphical representation of elements in the Logic Pro Environment. These elements can be used to create and process MIDI data in real time, and can even be used to create processing machines, such as virtual rhythm generators or step sequencers. Examples of Environment objects include instruments, multi-instruments, faders and arpeggiators, amongst others. The Environment Mixer layer contains objects that process audio data.

Object Parameter box 

The Object Parameter box displays the properties of any selected Environment object.


The playback point in a source audio file can differ from the start point (anchor) of the file. This is known as an offset or start point offset. Offset is also used in conjunction with video time code, where the start time of the Logic Pro project and QuickTime movie file can be offset (different) from each other. A further use of the term is when the amplitude of a waveform is off-axis from the center line (due to a recording error caused by hardware). This can be rectified with the DC Offset function in the Sample Editor. See DC Offset.


Abbreviation for Open Track List. This file format, typically used for data exchange with Tascam hard disk recorders, such as the MX 2424, can be imported and exported by Logic Pro. The OpenTL file format only supports the exchange of audio data (audio regions, inclusive of track position information). MIDI and automation data are ignored when using the Logic Pro OpenTL export function.


Alternative function, often in the form of a checkbox, sometimes also available as a menu entry.


Modifier key, also known as the Alt key in MS Windows.


A synthesizer oscillator generates an alternating current, using a selection of waveforms that contain different amounts of harmonics.

output channel strip 

Channel strip type in the Mixer that controls the output level and pan/balance for each physical output of your audio interface.

Page view 

Score Editor view displaying notation as it will appear on the printed page.

pan, pan position 

The placement of mono audio signals in the stereo field, by setting different levels on both sides (see Balance).

Pan control 

Rotary knob (directly above the Level fader) on mono channel strips, that determines the position of the signal in the stereo image.

Parameter box 

Field on the left side of Logic Pro windows (or in the Inspector). It is used to adjust the parameters of the selected track, regions, events, or objects. Also see Inspector.


1) The highest level in an audio signal. 2) Portions of a digital audio signal that exceed 0 dB, resulting in clipping. You can use the Logic Pro level meter facilities to locate peaks and remove or avoid clipping. The Search Peak command in the Sample Editor Functions menu searches for the sample bit with the greatest amplitude value.

peak level display 

A digital audio meter that displays the absolute volume of an audio signal as it plays. So named because every peak in the signal can be accurately seen.

Pencil tool 

Tool used to create empty MIDI regions in the Arrange area. It can also be used to add audio regions to the Arrange area, when used in conjunction with the Shift key. In the Sample Editor, the Pencil can be used to draw out transient signal spikes (pops and clicks) in signals.

Piano Roll Editor 

A MIDI event editor that displays note events as horizontal beams. Events can be cut, copied, moved, and resized in a similar fashion to regions in the Arrange area.

pink noise 

A harmonic noise type that contains more energy in the lower-frequency range.


The perceived highness (treble) or lowness (bass) of a musical sound. Corresponds to the frequency of the sound wave.

pitch bend message 

MIDI message transmitted by the pitch bend wheel of a MIDI keyboard.


Playing an audio or MIDI region, an audio file, or an entire arrangement, allowing you to hear it.


The playhead is a vertical white line that indicates the current playback position in all horizontal, time-based Logic Pro windows (the Arrange area, for example). The playhead can be directly grabbed and moved with the mouse (see scrubbing).


Software application that enhances the functionality of the main program (in this case, Logic Pro). Logic Pro plug-ins are typically software instruments or effects.

plug-in window 

A window that opens when a plug-in is inserted, or the Insert/Instrument slot is double-clicked. Allows you to interact with the plug-in parameters.

Pointer tool 

Tool used to select or edit regions, events, menu or interface items, and more in Logic Pro.

post fader 

Sends in analog mixers are positioned either before (pre) or after (post) the fader. Post fader means positioned after the Volume fader in the signal flow, with the level of a signal going to the send changing along with the fader movements.

pre fader 

Sends in analog mixers are positioned either before (pre) or after (post) the fader. Pre fader means positioned before the Volume fader in the signal flow, so the level of a signal routed pre-fader to a send remains constant, regardless of any fader movements.

Preferences window 

A window that is accessed via the Logic Pro > Preferences menu. All Logic Pro preferences can be set in this window.


Set of plug-in parameter values that can be loaded, saved, copied, or pasted via the Settings menu in the plug-in window header. See setting and Settings menu.


See aftertouch.


A Logic document. It contains all MIDI regions and references to the audio files to be played back. A project file is saved within a project folder—which can contain the project’s audio files and other assets (such as video, sample files, and so on). Saving a project with assets simplifies archiving and exchanging projects, but increases the project folder’s size.

project folder 

In Logic Pro, the top-level folder that can contain all media associated with a project, including audio files, sampler instruments and samples, video, and other data.

project settings 

The project settings are a collection of program settings that are specific to the current project. These are different from the global preferences that affect all Logic Pro projects (see Preferences window).

protected track 

A protected track cannot have its contents moved or changed.

punch in, punch out 

Going into and out of record to replace a section of an existing recording. This process can be automated in Logic Pro. Also see Autopunch function.


Pulse Width Modulation. Synthesizers often feature this facility, where a square waveform is deformed by adjusting its pulse width. A square waveform usually sounds hollow, and woody, whereas a pulse width modulated square wave sounds more reedy and nasal.

Q factor 

A term generally associated with equalizers. The Q factor is the quality factor of the equalization, and is used to select a narrower or broader frequency range within the overall sonic spectrum of the incoming signal.


Time-correction of note positions by moving them to the nearest point on a selectable grid (this is chosen in the Quantization menu). When quantization is applied to any selected event or region, Logic Pro will move all note events to align perfectly with the nearest grid position. Logic Pro quantization is a non-destructive playback operation, allowing different quantize values to be auditioned while listening to your music.

Quantization menu 

Menu found throughout Logic Pro that determines the current quantization grid. See entries below.

Quantize button 

Button labeled with a Q. Performs the quantize operation (chosen in the Quantization menu) on selected events. Also see Quantize tool and quantization.

Quantize tool 

Tool labeled with a Q. It is used to apply quantization to specific (selected) events, using the quantize value specified in the Quantization menu of the Piano Roll Editor or Event List.

quick swipe comping 

A Take Folder Editing mode where you swipe across take sections with the mouse to create and edit comps. See drag editing.


QuickTime is an Apple cross-platform standard for digitized, data-compressed video playback and encoding. QuickTime movies can be run in a Logic Pro window or on a global Video track, in sync with the project. Whenever you move the playhead, the film follows and vice versa.


Abbreviation for random-access memory. Computer memory capacity, measured in megabytes (MB), determines the amount of data the computer can process and temporarily store at any given moment.

real-time effects 

Effects that can be applied to regions in real time, during playback. Real-time effects can be used on any Macintosh computer qualified to run Logic Pro.


Audio tracks must be manually armed (record-enabled) before you can record on them. MIDI and software instrument tracks are automatically record-enabled when selected.


The act of capturing a performance as audio or MIDI data into Logic Pro. The term is also commonly used when referring to the actual data (in Logic Pro, this is delineated by the use of the words region or file to make things clearer when discussing recordings).


ReCycle is the name of an application from software manufacturer Propellerhead, which mainly serves as an editing and production tool for loops (repeated audio samples). ReCycle uses specific file formats (.rex) which can be imported by Logic Pro.


Regions can be found on arrange tracks:  They are rectangular beams that act as containers for audio or MIDI data. There are three different types of regions:  audio regions, MIDI regions, and folder regions (usually referred to as folders). Also see audio region, MIDI region, and folder.

Region Parameter box 

Box in the upper-left corner of the Arrange window, used to non-destructively set the playback parameters for individual regions, including quantization, transposition, velocity, compression, and delay. These parameters do not alter the stored data. Rather, they affect how the events are played back.


An envelope parameter that determines the time it takes for a signal to fall from the sustain level to an amplitude of zero when the key is released. See envelope.

Replace mode 

A type of overwrite recording mode where the currently specified audio region in the Arrange area is replaced with the incoming signal. To activate Replace mode, click the Replace button in the Transport bar.


A term generally associated with filters, particularly those of synthesizers. Resonance emphasizes the frequency range surrounding the cutoff frequency. See cutoff frequency.


Reverb(eration) is the sound of a physical space. More specifically, the reflections of sound waves within a space. As an example, a handclap in a cathedral will reverberate for a long time as sound waves bounce off the stone surfaces within a very large space. A handclap in a broom closet will hardly reverberate at all. This is because the time it takes for the sound waves to reach the walls and bounce back to your ears is very short, so the reverb effect will probably not even be heard.


An audio streaming and synchronization technology from Propellerhead software. The output of ReWire applications can be routed into (and processed with) the Logic Pro Mixer. Logic Pro can also control the transport operations of ReWire programs. Further to these functions, Logic Pro instrument tracks can drive the software instruments of ReWire applications.


A gradual slowdown of tempo (see tempo).


Generally refers to the way audio is sent through processing units. Also often used to describe specific input and output assignments.


A digital recording of a sound at a particular instant in time.

Sample Editor 

The Logic Pro Sample Editor allows audio files to be destructively cut, reversed, shortened, changed in gain, and processed in a number of other ways. It allows editing of individual samples within an audio file consisting of thousands, or millions, of samples. The Sample Editor also provides access to a number of special sample processing tools, collectively known as the Digital Factory.

sample rate 

When an analog audio signal is converted to a digital signal, this term refers to the number of times per second the audio file is sampled. Logic Pro can record and edit audio at sample rates ranging from 44.1 kHz (44,100 times per second) up to 192 kHz (192,000 times per second).

sample rate converter 

Device or algorithm that translates one sample rate to another.


Device used for sampling. In Logic Pro, this generally refers to the EXS24 mkII software-based sampler.


The process of converting analog audio into digital information. The sample rate of an audio stream specifies the number of samples that are captured per second (see sample rate). Higher sample rates yield higher-quality audio.


A term most commonly associated with a slight tape distortion or the characteristics of tube amplifiers. It basically describes a very high gain level that causes a slight distortion of the incoming signal, resulting in a warm, rounded sound.


A group of related musical notes (or pitches) that forms the basis of the melody and harmony in a piece of music. The most common scales are the major scale and minor scale.

scan code 

Each key on a computer keyboard has a scan code rather than an ASCII symbol associated with it. As an example:  The Plus and Minus keys on the numeric keypad and the corresponding keys above the keyboard have a different scan code, but use the same ASCII symbol.

scene marker 

Logic Pro can automatically extract information from (abrupt) transitions in QuickTime movie files, and create a marker, making the process of scoring to film much faster and easier. Such transitions in video generally indicate a scene change.

Score Editor 

Logic Pro editor that deals with standard musical notation. MIDI note events are represented as quavers, crotchets, minims, and so on. The Score Editor allows you to adjust and edit the layout of the score, and print it.

score set 

A collection of various staff styles, staffs, and other elements shown in the Score Editor can be saved as a score set. This facility allows you to quickly switch between (and edit and print) different portions of the score, such as a brass section, in isolation to the entire score. It also simplifies experimentation with different layouts.


A layout of various windows, inclusive of all display parameters (zoom, position, size of each window, and so on) is called a screenset. You can swap between different screensets, much as you might swap between different computer monitors.

scroll bar and scroller 

Gray beam at the edge of a window. A movable box inside the beam is used to select the displayed project section in the window.


Sound Designer II audio file format. Very similar in structure to the AIFF file format.

search field 

In many Logic Pro windows you find a field with rounded corners and a magnifying glass to the left. This field allows you to perform text searches. As examples, the search fields in the Key Commands window or Loop Browser.


Self-oscillation is a typical characteristic of analog filter circuits. It occurs when the filter, at high-resonance values, feeds back into itself and begins to oscillate at its natural frequency.


Smallest interval between two pitches in the standard diatonic scale, equal to a half tone. A semitone is also called a half step or half tone.


Abbreviation for auxiliary sends. An output on an audio device used for routing a controlled amount of the signal to another device. Sends are often used to send several signals to the same effect, which is useful for computationally intensive effects such as reverb.

Send slot 

A panel shown on mixer channel strips that enables you to send (via a bus) a portion (or all) of the audio signal to an auxiliary channel strip. You may use multiple sends on channels.


A sequencer is these days considered to be a computer application that allows you to record both digital audio and MIDI data and blend the sounds together in a software mixing console. In earlier times, a sequencer controlled synthesizers via a series of control voltages and gates, or via MIDI only. No audio recording or control was available.


1) A parameter value. 2) A set of plug-in parameter values that can be loaded, saved, copied, or pasted via the Settings menu. A plug-in setting is also known as preset. Also see preset and Settings menu.

Settings menu 

Found in the gray header at the top of all plug-in windows. Allows you to save, load, copy, and paste settings:  the parameter values of effects and software instruments.


Channel strip settings, plug-in settings, and key commands can be stored and accessed (shared) on a local network or MobileMe account.

shelving EQ 

EQ type that allows the frequency range above or below the specified frequency to be increased or decreased.

side chain 

A side chain is effectively an alternate input signal—usually routed into an effect—that is used to control an effect parameter. As an example, you could use a side-chained track containing a drum loop to act as the control signal for a gate inserted on a sustained pad track, creating a rhythmic gating effect of the pad sound.

Signature List 

A Logic Pro window that lists all time and key signatures of a project.

Signature track 

Global track that shows all time and key signatures of a project.

Single Trigger mode 

This term is associated with synthesizers such as the ES1. In this mode, envelopes are not retriggered when tied (legato) notes are played.


See Standard MIDI File.


Abbreviation for Society of Motion Picture and Television Engineers. The organization responsible for establishing a synchronization system that divides time into hours, minutes, seconds, frames, and subframes (SMPTE time code). SMPTE time code is also used for synchronizing different devices. The MIDI equivalent of SMPTE time code is MIDI Time Code (MTC). See MTC.

SMPTE ruler 

In addition to the standard bar/beat display, the Logic Pro Bar ruler can display time units in SMPTE format:  hours, minutes, seconds, and frames, and can display time code if a video is imported into the project.

Snap pop-up menu 

A pop-up menu found in the local menu of linear editing windows. It determines the behavior of regions or events when edited; lengths and cuts will snap to the nearest possible position (as determined by the chosen Snap menu value), for example.

software instrument 

Software counterpart to hardware samplers or synthesizer modules, or acoustic sound sources such as drumkits or guitars. The sounds generated by software instruments are calculated by the computer processor, and played via the audio interface outputs. Often colloquially called softsynths or softsamplers.


A way to temporarily highlight one or more tracks or regions or events, allowing them to be heard in isolation.

Solo tool 

Click-holding individual regions or events with the Solo tool temporarily allows them to be heard in isolation. All other objects are muted.


Short for Sony/Philips Digital Interface, a standard transmission format for professional stereo digital audio signals. The format is similar to AES/EBU, but uses 75 ohm coaxial or optical connectors and cabling. Depending on the type of devices involved, AES/EBU and S/P-DIF coaxial interfaces can communicate directly. Most digital audio interfaces available today will feature S/P-DIF connectors.

split channel audio files 

Each channel of multi-channel audio files (stereo or surround) are usually dealt with together. These files are said to be interleaved. Edits to one channel will affect the others equally. Logic Pro allows you to separate these files, making them split channel audio files, enabling independent edits to each. Also see interleaved audio file.


Abbreviation for Song Position Pointer, a MIDI clock timing pulse sub-message that indicates the current “song” (project) position. It is accurate to bars (and beats for some devices), but is not as accurate as MIDI Time Code (MTC). If you have a choice of these two when synchronizing Logic Pro, choose MTC (see both the MIDI Clock and MTC entries).

staff style 

A staff style determines the appearance of notation on a musical staff. You can define note sizing and spacing, number of staff lines, fonts, and more for each staff style.

Standard MIDI file (SMF) 

Standard file format for exchanging songs between different sequencers or MIDI file players. Standard MIDI files are not specific to a particular sequencer program, type of computer, or device. Any sequencer should be able to interpret at least the type 0 MIDI file format. Standard MIDI files contain information about MIDI events, including time positions and channel assignments, names of individual tracks, instrument names, controller data, tempo changes, and more.

status byte 

First byte in a MIDI message, which determines the type of message.

Step Input function 

The Step Input function allows you to insert MIDI notes—one at a time—into a MIDI region, when Logic Pro is not in a real-time recording mode. This allows you to input notes that may be too fast for you to play, or may be useful if replicating sheet music, but you don’t sight read. Step input can be performed onscreen with the mouse or with the computer or MIDI keyboard, or any combination of these devices. Also see In button.

step sequencer 

While all sequencers, including Logic Pro, step through a series of events, this term is used to describe a device from the seminal years of analog synthesizers. Essentially, two rows of knobs (usually 8) were individually adjusted to control the gate time (note length) and pitch of a connected synthesizer. The sequencer would step through these knob settings once, or repeatedly. Many modern software instruments, particularly drum synthesizers, include an integrated step sequencer that synchronizes with Logic Pro playback. Ultrabeat incorporates a step sequencer which is considerably more flexible than its ancient analog cousins.


Short for stereophonic sound reproduction of two different audio channels. Compare with mono.


A sub-division of a SMPTE frame, corresponding to the individual bits of a SMPTE frame. One frame consists of 80 bits.


Surround indicates playback systems that make use of multiple speakers. The most common surround format is 5.1 channels (front left, front center, front right, left surround, right surround, and an LFE, or subwoofer, channel), typically used in home theater systems and in cinemas. Logic Pro supports all common surround formats, and provides surround recording, plug-in, and mixing facilities.

Surround Panner 

Replaces the standard Pan/Balance control of channel strips, set to Surround in the Output slot. Allows you to control the relative positioning of the channel signal between the speakers available (in the chosen project surround format).


An envelope parameter that sets the steady amplitude level produced when a key is held down. See envelope.

sustain pedal 

A momentary footswitch that is connected to MIDI keyboards. It transmits MIDI controller number 64, which is recorded and played back by Logic Pro.

Swing parameter 

Alters the rigid timing of a quantization grid by delaying every other note of a specified sub-division by a definable amount.

Sync button 

This button, found on the Transport bar, activates/deactivates external synchronization mode.


Method of keeping several recording or playback devices time-locked with one another. In virtually all synchronized setups, there will be one master device and one or more slave devices that derive their synchronization clock from the master.


Central unit used to control the synchronization of several devices. In most situations, Logic Pro will act as the master synchronizer.


A device (hardware or software) that is used to generate sounds. The word is derived from early attempts with mechanical and electronic machines to emulate (or synthesize) the sounds of musical instruments, voices, birdsong, and so on. Logic Pro features several software synthesizers, including the ES1, ES2, EFM 1, ES E, ES P, and ES M.


Abbreviation for System Exclusive data. SysEx data forms the top tier in the hierarchy of MIDI commands. These messages are tagged with an identification number for each manufacturer (the SysEx manufacturer ID number). The actual contents of these MIDI commands is left to the manufacturer. SysEx data is often used to transfer individual (or banks of) sound programs or system settings, or to address individual sound generation or signal processing parameters.

take folder 

A container for multiple take recordings.


A take, put simply, is a recording. Logic Pro allows you to create several takes, one after the other, without leaving record mode. These takes can then be compiled into a super take (see comping).


A project that contains settings and preferences that you have defined. Templates serve as a starting point for new projects (scoring tasks, audio only projects, MIDI only projects, and so on, as your personal needs require). Any project can be used as a template, and you can create and save multiple templates.


The playback speed of a piece of music, measured in beats per minute. Logic Pro allows you to create and edit tempo changes in the Tempo track.

tempo change 

An event inserted into the Tempo track (as a node) that indicates a change in tempo at a particular bar/beat position.

Tempo track 

One of the global tracks that displays tempo changes as nodes.


The smallest unit of timing resolution in a MIDI sequencer. In Logic Pro, this is 1/3840th of a note. Logic Pro can go down to single sample accuracy (at sufficient zoom levels) for edits and positioning, but the MIDI protocol is not fast enough to support this.

time code 

A format (and signal) for assigning a unique, sequential time unit to each frame of video or project position. The SMPTE time code format, for example, is measured in hours :  minutes :  seconds :  frames and subframes.


Measure of the ability to play notes at the right time. Timing can also refer to synchronization between events, regions, and devices.


To switch between two states such as on or off (applies to windows, parameter values, and so on).

Tool menu 

Available in the local menu bar of a window, containing tools for editing, zooming, cropping, and otherwise manipulating items in the window.


The top of the Arrange window features the toolbar, which is used to access or hide certain onscreen areas, such as the Media or Lists area or Inspector. It also contains a number of buttons for key functions, such as Locking/Unlocking SMPTE positions. You may freely customize the toolbar to meet your needs.


A horizontal row in the Arrange area that contains either audio or MIDI regions that can be played back over time. Each track has a specified destination (a channel strip) that data is routed to. Logic Pro allows hundreds of tracks to be used in a project.

track arming 

See record-enable.

track list 

Situated to the left of the Arrange area. Displays the channel strips assigned to various tracks as well as Track Solo, Mute, and other buttons.

Track Parameter box 

See Object Parameter box.

Track Protect button 

The button featuring the lock icon, shown in the Arrange track list, protects or unprotects tracks from further editing. Also see protected track.

transform set 

A collection of transform operations (performed in the Transform window) can be saved as a transform set. Saved transform sets can be quickly accessed via the Presets menu at the top-left corner of the Transform window. You may also import transform sets from other projects. See entry below.

Transform window 

Logic Pro editor that lets you define a set of conditions and operations that are used to select and manipulate specific MIDI events.


Position in an audio recording where the signal becomes a lot louder—over a short time span (a signal spike, in other words). As this is typical for drum recordings, transients can be used to indicate where beats occur in an audio signal.

transient detection 

A process where audio files are analyzed for transients the first time you enable a track for flex time editing. See flex time editing.

transient marker 

A marker that denotes a significant point or peak in an audio file.

Transport bar 

A field shown at the bottom of the Arrange window, used to control recording and playback functions. The Transport bar offers Record, Pause, Play, Stop, and Rewind/Forward buttons plus other functions. You can also open independent Transport bar windows by choosing Window > Transport (Command-7).


Transposition is the act of changing the pitch of an audio or MIDI region (or event) by a number of semitones.

Transposition track 

Global track component that shows transposition events.


Refers to high-frequency sounds or components within a sound. See frequency.

Undo function 

Function that reverses the previous editing operation. The Undo History allows multiple undo steps to be made.


Fundamentally, computers just deal with numbers. They store letters and other characters by assigning a number for each one. Unicode provides a unique number for every character, no matter what the platform, no matter what the program, no matter what the language.


A way of speeding up or slowing down the entire project, similar to the original varispeed feature of tape machines.


Force at which a MIDI note is struck; controlled by the second data byte of a note event.

Velocity tool 

This tool, found in the Logic Pro MIDI editors, allows the velocity of individual, or grouped, note events to be adjusted.

Video track 

A global track component that allows the viewing of video clips.

virtual memory 

Area of the hard disk used as an extension of RAM memory by the computer. The disadvantage is its very slow access time, in comparison to physical RAM.

Voice Separation tool 

You can separate polyphonic voices onto different staffs in the Score Editor by drawing a dividing line with the Voice Separation tool (provided you are using a polyphonic staff style).

VU meter 

Abbreviation for Volume Unit meter. An analog meter used to monitor audio levels.


The primary audio file format used by Windows-compatible computers. In Logic Pro, all recorded and bounced WAV files are in Broadcast Wave format, which includes high-resolution timestamp information that stores positional information. This makes it easy to align these files in other audio and video applications.


A visual representation of an audio signal. Waveform graphics run from left to right, and are centered on a horizontal line. Louder portions of the waveform (amplitude peaks) are indicated as taller spikes or higher curves in the waveform.

wet/dry mix 

Refers to the ratio of a signal that effects have been added to (wet), and the original, unprocessed signal (dry).

white noise 

Noise type that consists of all frequencies (an infinite number) sounding simultaneously, at the same intensity, in a given frequency band. Its name is analogous to white light, which consists of a mixture of all optical wavelengths (all rainbow colors). Sonically, white noise falls between the sound of the consonant F and breaking waves (surf). Synthesis of wind and seashore noises, or electronic snare drum sounds, requires the use of white noise.

window type 

Status of the window as a float window or a normal window. Float windows always float in the foreground and cannot be hidden by normal windows. Also see float window.

Word Clock 

Clock signal required by digital audio interfaces to ensure the sampling rates of connected devices run synchronously. When two devices are connected via a standard digital audio interface (such as S/P-DIF or ADAT optical), Word Clock is transmitted via the audio circuit. If you want more than two digital audio devices to communicate with each other, you will need to use separate Word Clock ports for synchronization, in most cases.

word length 

See bit depth.


Extended General MIDI standard from Yamaha, compatible with Roland GS.

zero crossing 

A point in an audio file where the waveform crosses the zero amplitude axis. If you cut an audio file at a zero crossing there will be no click at the cut point.


An action that enlarges (zooms in on) or shrinks (zooms out from) the display in a Logic Pro window. The Zoom tool, and the zoom controls found in the lower-left and upper-right corners of windows, are both used for zooming tasks. Also see zoom control and zoom level.

zoom control 

The control that appears at the bottom-right corner of some windows, such as the Arrange area. The zoom control slider allows you to navigate through the entire length of the currently displayed project. The lines on the left and right of the slider can be clicked to zoom in and out by a fixed percentage.

zoom level 

The amount that window contents (tracks and regions, for example) are magnified. Zooming in to a high level allows you to make more precise edits. Conversely, you can zoom all the way out to see the entire project and work on very large sections.

Zoom tool 

This tool allows you to zoom in on any part of the active Logic Pro window. You can choose this tool from the Toolbox, or activate it when using other tools by holding down the Control key and clicking.