Here's the trivia. One Beatle each did one of the following:
A) Made a cameo on Monty Python's Flying Circus.
B) Helped finance a Monty Python movie.
C) Produced a song by Monty Python's most frequent song contributor.
D) Said this in the 1970s: "Part of me would sooner be a comedian. I just don't have the guts to stand up and do it, but I'd love to be in the Monty Python, you know, rather than the Beatles, in a way."
Answers in a separate post! Guesses in the comments, as you do (comments screened for now; I'll unscreen them later). You can do this!
EDIT: Unless I've screwed up my memories of the Beatles and the Pythons, there should be a different Beatle for each letter. (Note, by the way, that this edit is JUST to add this note; I haven't changed how the questions are phrased.)
Later Edit: Answers posted! Behind a cut, if you still want to guess or just don't want to know.