I know I can't do anything about this one, but I'm going to throw it in anyway... people who request modern songs when you are playing in a historical context. I actually had someone ask me, at an 1850s event, if I knew Orange Blossom Special.

Oh, and this one... we were at an 18th century event where one of the PARTICIPANTS insisted on playing modern bluegrass tunes (they are old-timey, after all), and didn't seem to understand the concept of taking turns.

At this same event, after I did what I like to call "the bagpipe trick" on my fiddle, some guy says, oh, you didn't play such and such note. I said, here, you play it then. He backed off.

The other one is people who sing along loudly and either don't know the words or can't sing at all.

People who just assume we will play for free. Now, really, a lot of times we do, for local events. But we have been to events where other people were getting paid, and I sorta feel like, well, if you can pay them, then you can pay us too.

Someone already mentioned those people who tell you how much they enjoy your show, then never call you.

But to be fair... there are moments that make all the BS worthwhile. :-)