I'm intending this as a light-hearted collecting of funny stories about run-ins with people who want to tell others how to play music. I'm not talking about online run-ins, but situations where you were accosted while actually playing music. While most of them are sorely vexing at the time, they are usually funny in hindsight.

My favorite, which was actually funny even at the time, was when I was playing in a pseudo-medieval folkish band. The entertainment factor in that band was more important (I'm sad to say) than musicality, and historical accuracy wasn't even on our radar. That fact should have been obvious to any marginally knowledgeable listener. We were doing funny songs, acting out the parts, etc. We were playing in a pub.

If one plays for drunken people, one expects the occasional heckler. What set this one apart was that the heckler was a medieval music scholar; I think he was a university professor. He was so drunk I don't think he could stand up. He sat across the room roaring profanely at us about the proper pitch of A (I think he wanted A-415 instead of 440), the type of harmonies being used, the tuning of the instruments, and anything else he could think of that we were doing "wrong". It was surreal.

Any other bizarre stories?