David Joseph Smith was an American engineer and founder of the synthesizer company Sequential. Smith created the first polyphonic synthesizer with fully programmable memory, the Prophet-5, which had a major impact on the music industry. He also led the development of MIDI, a standard interface protocol for synchronizing electronic instruments and audio equipment.

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, which was widely used in the music industry. In the 1980s, Sequential was important in the development of MIDI, a technical standard for synchronizing electronic instruments.