Associated with the electronic music movement, a synthesizer is an electronic instrument, sometimes accessed through a keyboard, that creates and combines waveforms used stored acoustic instrumental samples, called wavetable synthesis, or electronically, using FM synthesis.
Nowadays, a distinction is sometimes drawn between early developments in electronic instruments that, while they bore the name synthesizer, did not produce sound in real time and synthesizers that do work in real time. The term composition machines has been proposed to cover early products such as the RCA Electronic Music Synthesizer® and the Siemens Synthesizer®, both produced in the 1950's.
After precursors in the late 1940's designed by Harald Bode and Hugh Le Caine, among others, sound-generating devices with remote operation by means of voltage control were developed. Commercial synthesizers appeared in 1964, which saw the introduction of Donald Buchla’s synthesizer called “Buchla®,” which he worked on with composer Morton Subotnick, Robert A. Moog’s modular synthesizer on which he collaborated with composer Herbert Deutsch, and Paolo Ketoff’s Synket. Buchla has chosen not to use the term synthesizer for his instruments.
Digital synthesis, which allowed programming of patches in the synthesizer’s software, rather than sound creation through filters or circuitry, entered the scene in 1971. Polyphonic synthesizers were introduced in the mid-1970's. And by the 1980's, offerings included additional timbres on storage media.
The Musical Instrument Digital Interface standard, abbreviated as MIDI, was introduced in 1983, and created a better replacement for voltage control. In that same year, Yamaha incorporated MIDI to create a digital synthesizer that included it, the DX7. Following the development of microcomputers in the mid-1980s that could link to MIDI synthesizers, the possibilities for timbre programming substantially increased.
Once digital recording of external sounds, called “sampling,” was both available and affordable, by the mid 1980s, it became the main generator of timbres for all electronic instruments. Timbre choices expanded to include non-musical sounds, as well as world instruments, animals, and other noises are available.