A Brief History of the Synthesizer

This overview showcases a few of the most significant developments in synthesizer history.

Precursors to the Synthesizer

It may surprise you to learn that the earliest seeds of modern electronic synthesizers began in the twilight years of the 19th century. In 1896/1897, an American inventor named Thaddeus Cahill applied for a patent to protect the principle behind an instrument known as the Telharmonium, or Dynamophone. Weighing in at a staggering 200 tons, this mammoth electronic instrument was driven by 12 steam-powered electromagnetic generators. This behemoth was played in real time using velocity-sensitive keys and, amazingly, was able to generate several different sounds simultaneously. The Telharmonium was presented to the public in a series of “concerts” held in 1906. Christened “Telharmony,” this music was piped into the public telephone network, because no public address systems were available at the time.

In 1919, Russian inventor Leon Theremin took a markedly different approach. Named after the man who masterminded it, the monophonic Theremin was played without actually touching the instrument. It gauged the proximity of the player’s hands, as they were waved about in an electrostatic field between two antennae, and used this information to generate sound. This unorthodox technique made the Theremin enormously difficult to play. Its eerie, spine-tingling (but almost unvarying) timbre made it a favorite on countless horror movie soundtracks. Incidentally, R. A. Moog, whose synthesizers would later garner worldwide fame, began to build Theremins at the tender age of 19.

In Europe, the Frenchman Maurice Martenot devised the monophonic Ondes Martenot in 1928. The sound generation method of this instrument was akin to that of the Theremin, but in its earliest incarnation it was played by pulling a wire back and forth.

In Berlin during the 1930s, Friedrich Trautwein and Oskar Sala worked on the Trautonium, an instrument that was played by pressing a steel wire onto a bar. Depending on the player’s preference, it enabled infinitely variable pitches—much like a fretless stringed instrument—or incremental pitches similar to that of a keyboard instrument. Sala continued to develop the instrument throughout his life, an effort culminating in the two-voice Mixturtrautonium in 1952. He scored numerous industrial films, as well as the entire soundtrack of Alfred Hitchcock’s masterpiece “The Birds,” with this instrument. Although the movie does not feature a conventional musical soundtrack, all bird calls and the sound of beating wings heard in the movie were generated on the Mixturtrautonium.

In Canada, Hugh Le Caine began to develop his Electronic Sackbut in 1945. The design of this monophonic instrument resembled that of a synthesizer, but it featured an enormously expressive keyboard, which responded not only to key velocity and pressure but also to lateral motion.

The instruments discussed thus far were all designed to be played in real time. Relatively early, however, people began to develop instruments that combined electronic sound generators and sequencers. The first instrument of this kind was presented by the French duo Edouard Coupleux and Joseph Givelet in 1929—the inspirationally named Automatically Operating Musical Instrument of the Electric Oscillation Type. This hybrid married electronic sound generation to a mechanically punched tape control. Generally acknowledged to be a mouthful, its unofficial name was shortened to Coupleux-Givelet Synthesizer by its builders; this was, incidentally, the first time a musical instrument was called a “synthesizer.”

The term was officially introduced in 1956 with the debut of the RCA Electronic Music Synthesizer Mark I, developed by American engineers Harry F. Olson and Herbert Belar. Its dual-voice sound generation system consisted of 12 tuning forks, which were stimulated electromagnetically. For its time, the instrument offered relatively sophisticated signal-processing options. The output signal of the sound generator could be monitored by loudspeakers and, amazingly, recorded directly onto two records! A single motor powered both turntables and the control unit of the Mark 1. The synthesizer was controlled by information punched onto a roll of paper tape, which actually enabled continuous automation of pitch, volume, timbre, and envelopes. It was as complicated as it sounds-handling was anything but a dream, and spontaneous playing was impossible.

The First Voltage-Controlled Synthesizers

With the exception of the Telharmonium, which was conceived prior to the advent of the thermionic valve, these precursors to the modern-day synthesizer were all based on tube circuitry. This made these instruments relatively unwieldy and certainly volatile. After the transistor became available in 1947/48, more rugged, smaller, and thus portable, instruments were soon to come.

At the end of 1963, American innovator R. A. (Bob) Moog met the composer Herbert Deutsch, who inspired Moog to combine a voltage-controlled oscillator and amplifier module with a keyboard in 1964—the first prototype of a voltage-controlled synthesizer. This collaboration with the German musician prompted Moog to extend his range of modules and to combine them into entire systems. It wasn’t until 1967, however, that Moog actually called his diverse mix-and-match systems synthesizers.

Moog’s achievements spread by word of mouth, and Moog, always keen to elicit the feedback of his customers, continued to add further modules to his line. Wendy Carlos’ LP release “Switched-On Bach” (1968) was responsible for the breakthrough of Moog’s instruments. The record featured Moog’s modular synthesizers and was one of the earliest commercial multitrack recordings. The album’s success introduced the synthesizer to a wider audience and made the name Moog synonymous with the instrument. Hoping to capitalize on the new sounds that synthesizers made available, and match Carlos’ commercial success, numerous studios, producers, and musicians acquired Moog modular synthesizers. In 1969, as many as 42 employees produced two to three complete modular systems every week at Moog’s production facility.

Working independently, an engineer named Donald Buchla had conceived and implemented the concept for a modular, voltage-controlled synthesizer. This coincided with Moog’s version. Buchla also developed his first instruments in close cooperation with users. The inspiration for his first synthesizer originated with composers Morton Subotnik and Ramon Sender, of the San Francisco Tape Music Center. Although he began working on this instrument in 1963, it didn’t make its public debut until 1966. By design, Buchla’s instruments catered primarily to academia and avant-garde musicians, so they never garnered the public attention and acclaim of Moog’s synthesizers.

Compact and Cheap

These early voltage-controlled synthesizers were modular.One (or several) chassis housed the power supply and the actual modules. The inputs and outputs of the modules had to be interconnected via a confusing tangle of patch cords before the synthesizer would actually make a sound. Establishing these connections properly was an art unto itself, and obtaining useful settings on the modules required significant expertise.

Moog realized that these modular synthesizers were too complex and expensive for the average musician and were likely to fail if sold through traditional music retailers. In 1969, Moog collaborated with engineers Jim Scott, Bill Hemsath, and Chad Hunt to design a compact, portable, affordable, and easy-to-use synthesizer. After three prototypes were built, the Minimoog Model D was released in the summer of 1970.

Unlike previous modular synthesizers, it was neither necessary (nor possible) for players to connect the modules of the Minimoog as they saw fit. All of the modules’ connecting circuitry was hard-wired at the factory. The type and number of modules was also fixed. This simplified manufacturing considerably, and cut costs dramatically. Hard on the heels of a major marketing campaign, the Minimoog became a huge success. Without alteration in its basic design, 13,000 Minimoogs were sold worldwide, right up to 1981.

Storage and Polyphony

Customers weren’t entirely satisfied, however. Although musicians no longer had to contend with countless cords in order to play a synthesizer, they still had to deal with loads of knobs and switches before they could do something as simple as switch from one sound to another. Moreover, keyboardists were bored with playing monophonic melody lines on synthesizers—they wanted to be able to play chords. Although dual-voice keyboards that connected two monophonic synthesizers were available as early as 1970, customers wanted more.

Attempting to satisfy these demands, two schools of thought emerged in synthesizer design. One approach called for an independent, monophonic synthesizer to be assigned to every key on the keyboard. To this end, designers married the design principles of electronic organs to synthesizer technology. Although this breed of instrument was fully polyphonic—all notes of the keyboard could be heard simultaneously—it wasn’t as versatile in its control options as a true synthesizer. The first fully polyphonic synthesizer to feature this type of design was the Moog Polymoog, released in 1975. Developed primarily by David Luce, it featured 71 weighted, velocity-sensitive keys.

In the second approach to polyphonic sound generation, a synthesizer was assigned to a key only when the key was pressed—in effect, semi-polyphony. As early as 1973, American company E-MU Systems introduced the Modular Keyboard System Series 4050, a digital keyboard that could be connected to up to ten monophonic synthesizers, and thus had ten-voice polyphony. The problems with this approach are obvious—very few people owned ten synthesizers, and the amount of time and effort involved in programming the settings for a new sound were an overwhelming deterrent. Digital memory was still waiting to be developed and, once again, the evolution of semi-polyphonic synthesizers required the desirable qualities that only digital keyboards could provide.

The same prerequisite-digital engineering—eventually led to synthesizers that allowed sounds to be stored. Without the benefit of digital technology, early attempts at storing sounds included some unwieldy solutions. As an example, a synthesizer with analog programmability required a dedicated row featuring all of the instrument’s control elements, for every “memory” slot! In this case, a selector switch accessed one of the many identical control panels and connected it to the sound generator.

The first synthesizer featuring storage slots implemented in this manner was the GX1, which Yamaha released in 1975. The control elements for the system’s storage slots were so small that they could only be adjusted using jeweller’s screwdrivers and complicated tools—called programmers and comparators.

It was not until 1978 that the problem was resolved satisfactorily. The five-voice polyphonic Prophet-5, released by American company Sequential Circuits, was the world’s first synthesizer with a global storage facility. All settings for each of its five onboard monophonic synthesizers were stored in memory slots—40 in the debut model. Moreover, all five synthesizers shared a single user interface, which simplified matters considerably. In spite of its initially steep price, this instrument proved extremely popular and approximately 8,000 were built, up until 1985. In addition to its digitally implemented polyphony and memory, the success of the Prophet-5 is attributable to the outstanding quality of its analog sound generation system.

Digital Synthesizers

Even modern digital synthesizers featuring variable polyphony, memory, and completely digital sound generation systems follow this semi-polyphonic approach. The number of voices that these instruments are able to generate, however, is no longer dependent on the number of built-in monophonic synthesizers. Rather, polyphony depends entirely on the performance capability of the computers that power them.

The breathtaking developments in the digital world are best illustrated by the following example. The first program that emulated sound generation entirely by means of a computer was Music I, authored by the American programmer Max Mathew. Invented in 1957, it ran on a university mainframe, an exorbitantly expensive IBM 704. Unimpressively, its sole claim to fame was that it could compute a triangle wave, although doing it in real time was beyond its abilities.

This lack of capacity for real-time performance is the reason why early digital technology was used solely for control (and storage) purposes in commercial synthesizers. Digital control circuitry debuted in 1971 in the form of the digital sequencer found in the Synthi 100 modular synthesizer—in all other respects an analog synthesizer—from English company EMS. Priced out of reach of all but the wealthiest musicians, the Synthi 100 sequencer featured a whopping total of 256 events.

Ever-increasing processor performance made it possible to integrate digital technology into parts of the sound generation engine itself. The monophonic Harmonic Synthesizer, manufactured by Rocky Mountain Instruments (RMI), was the first instrument to do so. This synthesizer had two digital oscillators, combined with analog filters and amplifier circuits.

The Synclavier, introduced in 1976 by New England Digital Corporation (NED), was the first synthesizer with completely digital sound generation. Instruments like the Synclavier were based on specialized processors, which had to be developed by the manufacturers themselves. This development cost made the Synclavier an investment that few could afford.

An alternative solution was the use of general-purpose processors made by third-party computer processor manufacturers. These processors, especially designed for multiplication and accumulation operations—common in audio processing tasks—are called digital signal processors (DSPs). Peavey’s DPM-3, released in 1990, was the first commercially available synthesizer completely based on standard DSPs. The instrument was 16-note polyphonic and based mainly on three Motorola 56001 DSPs. It featured an integrated sequencer and sample-based subtractive synthesis, with factory presets and user-definable samples.

Another solution was to design synthesizers as a computer peripheral, rather than as a standalone unit. The growing popularity of personal computers from the early 1980s made this option commercially viable. Passport Soundchaser and the Syntauri alphaSyntauri were the first examples of this concept. Both systems consisted of a processor card with a standard musical keyboard attached to it. The processor card was inserted into an Apple II computer. The synthesizers were programmed via the Apple keyboard and monitor. They were polyphonic, had programmable waveforms, envelopes, and sequencers. Today’s sound cards, introduced in countless numbers since 1989, follow this concept.

Exploiting the ever-increasing processing power of today’s computers, the next evolutionary step for the synthesizer is the software synthesizer, which runs as an application on a host computer.

The sound card (or built-in audio hardware) is needed these days only for audio input and output. The actual process of sound generation, effects processing, recording, and sequencing is performed by your computer’s CPU—using the Logic Pro software and included instruments.