During the 1970s, bands such as Pink Floyd created a lucrative market for the mass production of unofficial recordings with large followings of fans willing to purchase them.
In addition, the huge crowds that turned up to these concerts made the effective policing of the audience for the presence of recording equipment virtually impossible.
The track list consists of "Tunings", "Astronomy Domine", "Careful with that Axe, Eugene", "Interstellar Overdrive", "Set the Controls for the Heart of the Sun" and "A Saucerful of Secrets" In January 1996, the label See For Miles Records released the bootleg album "Psychedelic Games for May" which includes a collection of Syd Barrett era Floyd, featuring a pre-Floyd acetate, rough mixes of the early singles plus BBC TV and the unreleased single "Scream Thy Last Scream".
With the advent of a 1997 deluxe reissue of the movie soundtrack on a double compact disc, four previously unreleased Pink Floyd out-takes were also revealed.
Almost simultaneously, a 15-track bootleg CD of the complete sessions appeared that revealed additional works in progress, among them a track that was long referred to by Pink Floyd as "The Violent Sequence".
It was penned by Richard Wright for a riot scene in the movie and although unreleased in any form officially, was incorporated into their live set as an acoustic piano piece in the early part of the year.
The bootleg Supine in the Sunshine contains an audience live recording with extended versions of two songs from the soundtrack Obscured by Clouds (1972); namely the title track (5:38) and "When You're In" (7:48).
[17] The record was issued with the lyrics to the songs, and the quality of presentation convinced a number of buyers that the album was a bona fide follow-up to The Dark Side of the Moon.
They were the only band not to be verbally introduced; instead the house and stage lights were darkened while the introduction to "Speak to Me" was played, accompanied on the video screens by an animated version of the heart monitor graphic from The Dark Side of the Moon sleeve.
The bootleg label The Godfather released in March 2011 an 8-CD box set of Pink Floyd songs called The Complete Rainbow Tapes.