You can use the global tracks to change global events such as time signature and key during a project. The following section summarizes how these changes in the global tracks affect the playback of Apple Loops. Exceptions are the Tempo and Beat Mapping Tracks, as Apple Loops adjust automatically to the tempo of these tracks.
Apple Loops can contain information about their original key, and can be transposed automatically. They are played back at the project key by default, which is defined by the first key signature event. No distinction is made between major and minor keys for these global transposition functions; in fact, only the root of the initial key signature is relevant for playback of Apple Loops.
Note: When you change the key signature after importing Apple Loops, the playback of SIALs is not affected. They behave like normal MIDI regions. The playback of MIDI regions is not affected by key signature changes, only the display in the Score Editor.
The playback transposition for Apple Loops is controlled by the root note of chords in the Chord track. These root notes determine the global playback transposition—relative to the current key signature—shown in the Signature track. If no chords are available in the Chord track, the global playback key for Apple Loops is determined by the very first key signature in the Signature track (default: C major).
The root notes of chords in the Chord track determine the transposition (pitch shifting) of all Apple Loops.
The Change Display Only mode does not work with Apple Loops used on audio tracks. This shouldn’t pose a problem, as you won’t normally need this function when working with Apple Loops. There is one exception, however: some Apple Loops contain chord progressions. These chord progressions are not displayed in the Chord track. Unfortunately, you can’t use the Chord track’s Change Display Only mode to match the displayed chords to what is actually being heard. All changes in the Chord track affect the transposition of (audio, not instrument) Apple Loops. Activating the Change Display Only option doesn’t help.
Cut the (audio) Apple Loops file at the precise positions of any chord changes.
Match the chords displayed in the Chord Track with the chord progression in the cut Apple Loops files by manually entering the chords of each section in the Chord track. The individual Apple Loops parts will then be transposed accordingly.
Enter the inverted Transposition values of the chord root note changes in the Region Parameter box of each section, so that playback of the Apple Loops parts will match the original Apple Loops file.
For example, assuming a default project key of C:
The (audio) Apple Loops file contains a chord progression with root notes of C, F, G, and C. Cut it at these chord change positions. This will result in four regions.
Enter C, F, G, and C at the corresponding positions in the Chord track. Assuming the original key is C, this is equivalent to a transposition of the second region by +5 and the third region by +7 semitones. If you played the entire part at this point, the original audio material would be transposed by the amounts just entered in the Chord track, which isn’t what you want.
Set the Transposition value of the second region to −5, and of the third region to −7 in their respective Region Parameter boxes.
Playback of the whole part will now sound as it did before the cuts, and the correct chords are displayed in the Chord track.
Transposition events are closely linked to the progression of the chord root notes in the Chord track: Changing a chord root will be reflected in the Transposition track, and vice versa. Any alteration or creation of a transposition event will generate or alter the corresponding chord in the Chord track. All Apple Loops and MIDI regions will be pitch-shifted accordingly.
Note: Standard audio regions (audio regions that are not Apple Loops) will not be affected. Nor will Apple Loops that do not have a Key definition (drum loops, for example).
The global Transpose track transposes Apple Loops used on audio tracks by a maximum of that great when transposed over a greater range. This is also true for the Transposition parameter of the Region Parameter box.
Transposing an Apple Loops file to a higher pitch may result in the loop being played back at a lower pitch, and vice versa.
For example, if an Apple Loops file is transposed to sound seven semitones higher, it will actually play back five semitones lower. This is harmonically correct transposition, but it’s probably not to the intended octave.
Transposing audio material is a technically complicated process that always implies a certain loss in quality. The greater the transposition range, the more significant the loss in quality. This is why Apple Loops are always transposed by the smallest possible value.
You should note that sound quality is dependent on the transposition amount of the Apple Loops file’s original key—not the project key, which defines the zero line of the Transposition track. For example, if the project key is already five semitones above the original key of an Apple Loops file, setting the transposition value to +2 will transpose the Apple Loops file downwards by ten semitones. This is because the transposition value is only five semitones below its original key (rather than seven semitones above it).
In the classical European music system, an octave is divided into 12 semitones. As +7 semitones is harmonically equal to −5 semitones, a value of −5 is used as the transposition amount. The same happens with other settings: A transposition value of −9 will result in +3, and +12 will result in ± 0. The use of the nearest harmonically equal transposition option is based on delivering the best sonic results, with smaller transpositions being desirable.