Morton Subotnick (b. 1933) is an electronic music composer from Los Angeles. While not among the earliest pioneers of the genre, he expanded the range of its generally atonal and arrhythmic abstractions to allow sections with regular rhythms and tone patterns. This was made possible by one of the first synthesizers with a sequencer, built by Don Buchla to Subotnick's specifications. In 1962, Subotnick co-founded the non-profit educational electronic music studio, the San Francisco Tape Music Center. In 1967, Nonesuch Records commissioned this work from him, Silver Apples of the Moon. If you have 31 minutes to listen to bleeps and bloops, this is the one to hear!
Wikipedia article: Morton Subotnick