The best selling English language single of all time in Japan is "Beautiful Sunday" by Daniel Boone. It was used as a theme song for a tv show.
I remember hearing on American Top 40 that Leo Sayer didn't know he had recorded "You Make Me Feel Like Dancing" until he heard it on the radio. He was joking around in the studio with the musicians and someone hit the record button.
And apparently they didn't bother to check with Richard Berry, who actually wrote the song, not the poor, unsuspecting souls in The Kingsmen
John Entwistle wrote "Boris The Spider" in 10 minutes because he needed an extra song for the A Quick One LP.
two parter: Stephen Bishop played the folk singer who had his guitar smashed by Belushi in Animal House and Bishop was hooking up with Karen Allen (who was in Animal House) and wrote a couple songs about her on one of his albums, that also featured Eric Clapton
According to this, it was Floyd, Zeppelin and Elton John: Monty Python: Nineteen facts about the legendary comedy troupe you might not know » But they don't cite any sources. The production company credits on IMDB are as follows, but I suppose the bands could have given money privately to the Pythons: Michael White Productions National Film Trustee Company Python (Monty) Pictures
I don't see this one in a search of the thread and it's about my favorite: The night in 1973 when Pete Townshend calls out to an audience at San Francisco's Cow Palace for a drummer in the house 'cause Keith has passed out and can't be revived. Teenage Who fan - Scott Halpin - crawls onto stage and plays the rest of the set. I live vicariously through that moment imagining how exciting that would have been had I had the opportunity to sit in with Roj and the rest.
Stephen Bishop also recorded the closing theme song for Animal House and the song "Dream Girl" heard during the movie.
I was working from an erroneous memory. A check of HandMade Films on Wikipedia showed that it was The Life Of Brian that was funded by George Harrison. I apologize for the error.
