In 1977, Dave designed the Prophet-5, the world’s first fully-programmable polyphonic synth. In 1981, he co-developed the MIDI spec. Dave also worked with Yamaha on physical modeling synthesis and with Korg producing the Wavestation. In 1997 he developed the first professional soft synth Reality. In 2002 he founded DSI, now Sequential. The company currently produces hi-quality professional synthesizers, including the Prophet line, currently Prophet 5 and 10, Prophet 6, Prophet X, as well as the REV2 and OB-6 polysynths, Pro 3 multi filter mono/paraphonic synthesizer and Take 5 polysynth.