Undertaker, your hint wasn't too much help, as that's one of their few albums I never got! Let me try with their producer, George Martin, who played piano on a number of their albums, including the Help album. Otherwise, how about Billy Preston, who played the organ on a number of their releases. Here's a question which I have no idea why I remember it--in the late 60s, there was a group (SF based, I think) which recorded a song "Endless Tunnel", an extremely forgettable acid-rock anthem along the lines of the Doors' "The End". If you listened to WNEW-FM in NYC in the late 60s, you might remember it. Name the group.
