For the first time, the Beatles sing the Stones

George Harrison and Ringo Starr were filmed as they jammed a version of "Jumpin' Jack Flash" during a rehearsal at Madison Square Garden. They are part of a mini supergroup, which also includes Eric Clapton and Leon Russell, seen practising for the legendary Concert for Bangladesh which took place in New York in 1971. The footage has not been seen since it was recorded on the eve of the show, and is to be released on DVD on 24 October.

The people behind the release came across the low-key performance as they trawled through around 150 hours of material which has been kept in the archives of the Beatles' company Apple. "We were lucky enough to discover this fantastic rehearsal footage which had just been sitting in the archive for 34 years. It was an incredible treasure trove," said the DVD's director and editor, Claire Ferguson.

Although the Rolling Stones recorded Beatles songs, the reverse was not true. Indeed, it was when Mick Jagger and his bandmates recorded a version of "I Wanna Be Your Man", written for them on the spot in 1963 by John Lennon and Paul McCartney, that they decided to write their own songs because they realised that was where the money could be made.

Jagger and Keith Richards also added their backing vocals to the Beatles' "All You Need Is Love" in June 1967, with Jagger doing the same again days later when the song was performed during the first worldwide live satellite broadcast, Our World.

Harrison's hastily arranged Concert for Bangladesh was the first fundraising concert on such a scale and paved the way for 1985's Live Aid.