The first six minutes of the song is dominated by a memorable, "endless, droning minor-key riff", a guitar and bass ostinato. It is used as the basis for extended organ and guitar solos, then silenced to make way for a drum solo, one of the first on a rock record and one of the most famous, because of its surreal tribal sound. Bushy removed the bottom heads from his tom-toms to give them less of a resonant tone, and during the recording process, the drum tracks were subjected to a process known as flanging, producing a slow, swirling sound. The solo is followed by an ethereal polyphonic organ solo (which resembles variations on "God Rest Ye Merry, Gentlemen") to the accompaniment of drums (beginning around 9:20 into the piece). There are then interludes in cut time and a reprise of the original theme and vocals.

The recording that is heard on the album was meant to be a soundcheck for engineer Don Casale while the band waited for the arrival of producer Jim Hilton. However, Casale had rolled a recording tape, and when the rehearsal was completed it was agreed that the performance was of sufficient quality that another take was not needed. Hilton later remixed the recording at Gold Star Studios in Los Angeles.

"In-A-Gadda-Da-Vida" is the background music during a party scene in The A Team's episode Beneath the Surface.

"In-A-Gadda-Da-Vida" originally entitled "In the Garden of Eden" but at one point in the course of rehearsing and recording, singer Doug Ingle became intoxicated and slurred the words, creating the mondegreen that stuck as the title.

The band had been booked to play at Woodstock but got stuck at an airport. When their manager called the promoters of the concert they explained the situation and asked for patience. However, the manager demanded that the Butterfly be flown in by helicopter, whereupon they would "immediately" take the stage. After their set they would be paid and flown back to the airport. The manager was told that this would be taken into consideration and he would be called back. According to drummer, Ron Bushy, "We went down to the Port Authority three times and waited for the helicopter, but it never showed up."

When Iron Butterfly reformed in 1968 after a brief split, musicians rumored to have been interested in joining as lead guitarist include Neil Young, Jeff Beck, and Michael Monarch. Doug Ingle and Ron Bushy eventually decided upon Erik Brann.

Led Zeppelin opened for Iron Butterfly. A year to the day later Iron Butterfly opened for Led Zeppelin. The ironic twist continued with the band Yes, with whom drummer Ron Bushy is pals.