Carnival of Light
Carnival of Light was an experiment that was never released.
After finishing up Penny Lane on January 5, 1967, the Beatles turned to making this track for the Million Volt Light and Sound Rave, which was scheduled for later in the month in London. The connection was through Paul, who had commissioned a psychedelic design for a piano in his home from artist David Vaughan. Vaughan asked Paul to contribute a track to the upcoming avant-garde event, which he and his partners (Binder & Edwards) had created for putting a spotlight on electronic music and light displays.
Most Beatles experts consider this track to be a bizarre aberration, with no discernible melody, no sustained rhythm, and no coherent lyrics. It is a collage of organ sounds and drums with a few notes from highly-distorted guitar, and sound effects like water bubbling up. Paul and John scream, rather than sing, and they only say a few words at random: "Barcelona" and "Are you all right?"
The base track is organ pedal notes, slowed by half to drop the notes another octave and to cut the tempo in half. Reverb is used liberally, together with native American war cries, sighs into the microphone, and bits of background talk. Overdubs create pulses of audio feedback, silent movie organ, upright piano and more shouts from the vocalists. Finally, you hear Paul asking to have it played back to him, and the track ends unceremoniously, after around 14 minutes.
Paul sought to make it part of Anthology 2 in 1996, but George voted against its inclusion as being excessively avant-garde (meaning essentially he thought the recording was a piece of garbage).
McCartney still holds the master tapes of this track and has been keen on releasing it, but that would require the agreement of Ringo and the estates of John and George.
In 2009 a Russian bootleg called Now and Then (Raskol Records) contained a long track purporting to be Carnival of Light. Several phony reconstructions have also appeared over the years, but as of 2010, the official version remains under seal. In other words, all the version circulating on the net and especially on Youtube are fakes.