Synthesizer
An instrument that builds its sound from scratch with electronics rather than playing back or amplifying something that already makes noise.
The RCA Mark II of 1957 filled a room at the Columbia–Princeton centre and was programmed with punched paper. The practical breakthrough came in 1964, when Robert Moog and Don Buchla independently built modular systems in which oscillators, filters and amplifiers were patched together with cables and driven by control voltages. The Minimoog of 1970 hard-wired the patch and fitted on a stage. The Prophet-5 in 1978 added a microprocessor that remembered sounds, and the DX7 in 1983 went fully digital.
The synthesis method varies — subtractive, FM, wavetable, sampling, physical modelling — but the building blocks don't: a sound source, something to shape the timbre and an envelope to shape it over time. Since the late nineties most synths have been software inside a DAW, with the analogue ones surviving as the expensive option.