I don't have any disaster stories. There is a local-talent bluegrass & country show twice a year in the town where I go to college (town population 8900, so it's not a big show), and our lead fiddler, who is also the one who has all the contacts and does most of our PR, dropped his bow and accidentally said, "Sh*t" into the microphone in front of an audience consisting almost entirely of the 70+ crowd (and the rest were their 6-year-old grandkids). Caused some nervous laughter but we got over it.

We played a pretty good joke on the audience at one of those shows. We had about 6 band members and all of us came on stage with banjos--five-strings, four-strings, mando-banjo, all kinds of banjos--and started playing. I don't even play the banjo, I just did chords. Then we had the emcee yell at us that there was a town ordinance against having more than two banjos on stage at once, so, one by one, the non-banjo players went offstage and got their real instruments. It was pretty funny.

I think the worst music occurrence ever must have been the accordion recital that a friend of mine attended. 146 accordions in one room.