Dave Smith, whose synthesizers shaped electronic music

Dave Smith, a groundbreaking synthesizer designer, died on May 31 in Detroit. He was 72. The cause was complications of a heart attack, said his wife, Denise Smith. Smith, who lived in St. Helena, Calif., had been in Detroit to attend the Movement Festival of electronic music, which ran from May 28 to 30, and died in a hospital. A statement from Smith’s company, Sequential, said, “He was on the road doing what he loved best in the company of family, friends and artists.”

Smith introduced the first polyphonic and programmable synthesizer, the Sequential Circuits Prophet-5, in 1978. It was used on 1980s hits by Michael Jackson, the Cars, Madonna, Peter Gabriel, Talking Heads, a-ha, Duran Duran, Genesis, the Cure and Daryl Hall & John Oates. Over the next decades, instruments designed by Smith were embraced by Radiohead, Arcade

Fire, Dr. Dre, Flying Lotus, Nine Inch Nails and James Blake, among many others. In the early 1980s, Smith collaborated with Ikutaro Kakehashi, the founder of the Roland instrument company, to create MIDI (Musical Instrument Digital Interface), a shared specification that allows computers and instruments from diverse manufacturers to connect and communicate, making for countless sonic possibilities.

Justin Vernon, who records as Bon Iver, wrote on Twitter, “Dave Smith made the best keyboards ever … that’s saying it lightly.” Denise Smith said in an interview: “He loved the people who used his instruments. He was very curious about how they used his instruments, how they made them sound.”

In 1974, he started a company to build sequencers, Sequential Circuits — at first as a nights-and-weekends project, then as a full-time job, eventually as a company with 180 employees.

Unlike a piano or organ, early synthesizers, like the Moog and ARP, could generate only one note at a time. Shaping a particular tone involved setting multiple knobs, switches or dials, and trying to reproduce that tone afterward meant writing down all the settings and hoping to get similar results the next time.

The Prophet-5, which Smith designed with John Bowen and introduced in 1978, conquered both shortcomings. Controlling synthesizer functions with microprocessors, it could play five notes at once, allowing harmonies. Smith’s small company was swamped with orders; at times, the Prophet-5 had a two-year backlog.

In 1981, Smith and Chet Wood, a Sequential Circuits engineer, presented a paper at the Audio Engineering Society convention to propose “The ‘USI’, or Universal Synthesizer Interface.” The point, he recalled in a 2014 interview with Waveshaper Media, was “Here’s an interface. It doesn’t have to be this, but we all really need to get together and do something.” Otherwise, he said, “This market’s going nowhere.” Four Japanese companies — Roland, Korg, Yamaha, and Kawai — were willing to cooperate with Sequential Circuits on a shared standard, and Smith and Kakehashi of Roland worked out the details of what would become MIDI. In 2013, 30 years after MIDI was introduced, Smith and Kakehashi shared a Technical Grammy Award.