A synthesizer is an electronic musical instrument that generates audio signals. Synthesizers typically create sounds by generating waveforms through methods including subtractive synthesis, additive synthesis and frequency modulation synthesis. These sounds may be altered by components such as filters, which cut or boost frequencies; envelopes, which control articulation, or how notes begin and end; and low-frequency oscillators, which modulate parameters such as pitch, volume, or filter characteristics affecting timbre. Synthesizers are typically played with keyboards or controlled by sequencers, software or other instruments and may be synchronized to other equipment via MIDI.

The Moog synthesizer is a modular synthesizer invented by the American engineer Robert Moog in 1964. Moog's company, R. A. Moog Co., produced numerous models from 1965 to 1981, and again from 2014. It was the first commercial synthesizer and established the analog synthesizer concept.