Sequential is an American synthesizer company founded in 1974 as Sequential Circuits by Dave Smith. In 1978, Sequential released the Prophet-5, the first programmable polyphonic synthesizer; it became a market leader and industry standard, used by artists including Michael Jackson, Madonna, and John Carpenter. In the 1980s, Sequential was pivotal in the development of MIDI, a technical standard for synchronizing electronic instruments.
In 1987, Sequential went out of business and was purchased by Yamaha. Smith continued to develop instruments through a new company, Dave Smith Instruments. In 2015, Yamaha returned the Sequential Circuits trademark to Dave Smith Instruments, which rebranded as Sequential in 2018. In 2021, Sequential was acquired by the British audio technology company Focusrite.