Sequential Circuits (also known as Sequential or SCI) was a synth manufacturer formed in 1977. The founders were Dave Smith and John Bowen on the technical side, and Barb Fairhurst taking care of the business side of the operation. They released a sequencer, the Model 700, that year. In the meantime, they were working on the ground-breaking Prophet-5, which they released in 1978. The Prophet-5 dominated the market for polyphonic synthesizers until 1983. In the meantime, the company released a variety of variations on the Prophet-5 theme, both polyphonic and monophonic. The high point of this period was probably the Prophet-T8, an eight-voice synth with a piano-weighted keyboard with polyphonic aftertouch.