Two come immediately to mind, Jerry.

1) At an outdoor festival in an unnamed mid-Atlantic state, we were to perform on an open stage (a couple of pallets pulled together to raise us up off the ground), with a sound system (1 mic and two small speakers) that was plugged in about 200 yards up the hill from our stage. In between, there was a Welsh ladies' group making tea cakes, also plugged into the same extension cord. Whenever they turned on the electric skillet to cook the cakes, our sound system went dead - this went on for the entire afternoon festival.

2) A local (DC) booking agent booked the Boarding Party to play for a large convention's Friday evening gathering. The theme was to be 'The 4 Regions of America' - NE/SE/SW/NW
Each corner of the very large room was decorated with objects to represent that region, and in each corner was to be a group making music which was supposed to represent the region. Here's how it went:

NE- lobster pots, etc, and the Boarding Party singing shanties
SE - cotton bales, and a Dixieland band
SW - cactus plants, and a mariachi band
NW - spruce trees and a bluegrass band (?)

You will notice that every group was armed with instruments, except the Boarding Party (although the 5 of us at the time could sing pretty loud when required) There were no sound systems of any kind. What we didn't know was that all groups were to play simultaneously for 40 minutes at a time, with a 20 minute break and then go again!!
After about 2 sets, we had pretty well nackered our voices - and there was no Laphroaig around anywhere. The ultimate event that makes this a true bummer is that when we went to get paid, the booking agent 'didn't have his checkbook' - it took two weeks before we got our money.

Padre