Interstellar Overdrive

The piece was written in 1966. It began when Barrett tried to play on guitar a tune that manager Peter Jenner was humming, most often identified as Love's version of My Little Red Book, and used it as the main theme. Waters told Barrett the riff reminded him of the theme from Steptoe and Son. Barrett was inspired by the AMM guitarist Keith Rowe, and the free section took cues from Frank Zappa's Freak Out! and the Byrds' Eight Miles High. The album version was recorded in five takes on 27 February 1967, with a sixth on 16 March in an attempt at a shorter version. Producer Norman Smith, who was cutting the other songs down, let this one run, and he played the drum roll near the end.

Other versions and live

An early demo was cut on 31 October 1966 and used in Anthony Stern's film San Francisco. A January 1967 session at Sound Techniques produced a take of nearly 16 minutes, released on London '66-'67. The piece was dropped from the live set in 1970, with the last documented performance in Montreux on 22 November 1970. In 1969 Frank Zappa joined the band on stage for it at the Actuel Festival in Amougies, Belgium. Rolling Stone ranked the album version number 36 on its list of the 100 greatest guitar songs, and Death Grips sampled it in 2011.