David Joseph Smith (April 2, 1950 – May 31, 2022) 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. In 2005, Smith was inducted into the Mix Foundation TECnology (Technical Excellence and Creativity) Hall of Fame for the MIDI specification. In 2013, he and the Japanese businessman Ikutaro Kakehashi received a Technical Grammy Award for their contributions to the development of MIDI. Career Smith was born on April 2, 1950 in San Francisco. He had degrees in both Computer Science and Electronic Engineering from UC Berkeley. Sequential Circuits and Prophet-5 He purchased a Minimoog in 1972 and later built his own analog sequencer, founding Sequential Circuits in 1974 and advertising his product for sale in Rolling Stone. By 1977 he was working at Sequential full-time, and later that year he designed the Prophet 5, the world's first microprocessor-based musical instrument and also the first programmable polyphonic synth, an innovation that marked a crucial step forward in synthesizer design and functionality. Sequential went on to become one of the most successful music synthesizer manufacturers of the time. MIDI In 1981 Smith set out to create a standard protocol for communication between electronic musical instruments from different manufacturers worldwide. He presented a paper outlining the idea of a Universal Synthesizer Interface (USI) to the Audio Engineering Society (AES) in 1981 after meetings with Tom Oberheim and Roland founder Ikutaro Kakehashi. After some enhancements and revisions, the new standard was introduced as "Musical Instrument Digital Interface" (MIDI) at the Winter NAMM Show in 1983, when a Sequential Circuits Prophet-600 was successfully connected to a Roland Jupiter-6. In 1987 he was named a Fellow of the AES for his continuing work in the area of music synthesis. In 2005, Smith was inducted into the Mix Foundation TECnology (Technical Excellence and Creativity) Hall of Fame for the MIDI specification. In 2013, he and the Japanese businessman Ikutaro Kakehashi, the president of Roland Corporation, received a Technical Grammy Award for their contributions to the development of MIDI. In 2022, the Guardian wrote that MIDI remained as important to music as USB was to computing, and represented "a crucial value system of cooperation and mutual benefit,