Robert Moog Dies; Created Electronic Synthesizer

He added: "Raymond had everything adjusted so that, sure enough, when you played the keyboard you got the notes of the scale. But the really neat thing, as he pointed out, was that now you could glide from note to note -- you could play expressively -- you didn't have to play discrete notes."

This had a lasting impact on Dr. Moog as he completed his schooling: a bachelor's degree in physics from Queens College, a master's degree in electrical engineering from Columbia University and a doctorate in engineering physics from Cornell University, where he was famously late for his PhD defense.

According to the book "Analog Days" (2002), a history of the Moog synthesizer, Dr. Moog walked into an elevator on his way to the PhD defense and immediately became obsessed with the resonant frequency of the elevator: "Bob started jumping up and down on the floor [and] somewhere between the fourth and fifth floors he hit the right frequency. The elevator suddenly started bouncing alarmingly in time with his jumps and ground to a halt. Four hours later he was rescued."

At Cornell in the early 1960s, he met composer Herb Deutsch, a key advocate of electronic sounds. With inspiration from Deutsch, he created the analog synthesizer and promoted it successfully at an audio engineering society convention in the fall of 1964. A novel feature of his instrument was its attack-decay-sustain-release envelopes, which control the way notes swell and fade.

Dr. Moog called himself "a toolmaker with musicians for customers" and sought their advice on how he could improve his synthesizer. He installed a filter at the suggestion of electronic keyboardist Walter Carlos (later Wendy Carlos after a sex-change operation). After Carlos's "Switched-On Bach" album, Dr. Moog reaped a fortune for several years through sales at his workshop, based in Trumansburg, N.Y.

He developed a more portable instrument, the Minimoog, that also sold well, but competition, a recession and his admittedly poor marketing skills led him to sell his business, along with the rights to his Moog synthesizer name, in the early 1970s. After years of struggle, he regained the name in 2002.

By that time, he was long ensconced in the Blue Ridge Mountains of western North Carolina, where he ran a mail-order and retail electronics business now called Moog Music.

He cut a bizarre figure, with an ever-present pocket protector, a wave of white hair and a cautious but not always politic way with words. He drove a 1980 Toyota Tercel with a butterfly, snail and goldfish painted on the side and for years had a bumper sticker that read: "Theremin Players Do It With High Frequency!"

His marriage to Shirleigh Moog ended in divorce.

Survivors include his wife of nine years, Ileana Grams of Asheville; four children from his first marriage; a stepdaughter; and five grandchildren.