Hot Butter wasn't so much a group as an alias for keyboard virtuoso Stan Free, a top session player of the 1960s (with credits including work on albums by the Monkees, Arlo Guthrie, John Denver, et al), and a support musician or two working behind his Moog synthesizer. Free had cut several unsuccessful singles under his own name during the late '60s, and also had been a member of a Moog synthesizer ensemble, the First Moog Quartet, organized by Gershon Kingsley -- during their 1969 tour of the United States, the group had used Kingsley's dance instrumental "Popcorn" (which he had written and recorded in 1969 on his album Music to Moog By), as an encore, and it elicited some of the most positive reactions from audiences. Two years later, when Free issued a new recording of "Popcorn," he used the pseudonym Hot Butter; this was a shrewd marketing ploy, for not only did that name seem to fit together with the title of the piece better than "Stan Free" would have, but it also made it easier to remember and request the piece at record stores and on the radio -- some accounts say that Kingsley also played on that record, though he wasn't credited. Whoever was on it, the result was a Top Ten hit in America and England. Albums and other singles followed, mostly of classical works and familiar pop and movie tunes transcribed for synthesizer, but "Popcorn" remained his sole charting 45. It was popular enough to turn up as theme music and bridge-music for numerous television stations' productions, and is recognized today as an early forerunner of both disco music and synth pop. In 2000, the collected recordings of Hot Butter were issued on a single CD.