Electric Music for the Mind and Body

Sessions ran through the first week of February 1967. The backings were largely played live, and McDonald added his vocals afterward with the lights out, because he was self-conscious about being watched. Hirsh had joined on drums after John Francis-Gunning was fired, and the new lineup rehearsed at The Barn in the Santa Cruz Mountains before Christmas 1966. Not So Sweet Martha Lorraine and Bass Strings were taped on 1 February, Grace on 3 February, Flying High and Section 43 on 6 February, and Superbird on 7 February.

Charters took the tapes to Vanguard Studios in New York to edit and mix. He settled on a running order in which each side starts with the more commercial songs and moves toward the more psychedelic. The album came out on 11 May 1967, with a release party at the Fillmore that night. Sales were slow at first, and it peaked at 39 in September after the band played Monterey. Melton later said it was the band's best seller over the long run, and that Charters did not know how to record rock and roll, which left the records drier than the band sounded live. The original master tapes deteriorated, so the album was remixed in 1982 for its first CD release in 1990. A 2013 deluxe edition added the original mono and stereo mixes.

Bruce Eder called it one of the most important and enduring documents of the psychedelic era. Uncut called it a game changer. It is included in Robert Dimery's 1001 Albums You Must Hear Before You Die.