In the early 70's I became the bass player in Osiris, a band with the (now deceased) younger brother of the Dead's Pigpen. We played a gig near Palo Alto where some down on their luck guys living in a warehouse decided to pool their meager resources and put on a gig there so they could charge money and pay their rent.
So, you got two bands and all the beer you could drink for $3. This was even advertised on local radio, so a horde of hell raisin' party animals showed up. During the opening act, I was hanging out with our conga player in the front room when this completely red faced guy bursts in, shouting I want my money back! You promised all the beer I could drink and you've run out already!
Before the promoters could calm him down, he slugged one of them, knocking him out cold. As if on cue, like a Mel Brooks movie, everyone in the room seemed to suddenly turn to the person next to them and just started swinging haymakers. Chairs were being overturned, glass was shattering, the (few) women were screaming and the opening band even stopped. Momentarily, that is, then they cranked up even louder as if to provide a soundtrack for the action!
My bandmate and I slowly backed up against the wall, trying to be invisible before we were spotted and sucked into the vortex of flying fists and stomping work boots. Being the only two black people in a melee of 300 or so, we were kinda sticking out like sore thumbs so we just knew we were doomed (and with just a single punch we both would have crumpled like $2 umbrellas in a hurricane).
But just before the conflagration reached us, the cops finally showed up and restored order. They carted a fair share off to jail as they left and just when things were getting back to normal, suddenly a crazed maniac from across the room points and shouts to another guy standing right next to me something along the lines of, Jasper B-------! You **%^^&* snitch! You put me away for 4 years! I vowed if I ever found you I'd GET you! NOW I'VE FOUND YOU!!!!
As he's saying this he's practically foaming at the mouth and starts to move towards us. Literally 3 or 4 guys grab him and one shouts to the snitch (who's just standing there, transfixed), Don't just stand there, you fool. We can't hold this guy, forever. Run!.
Which he did...
When we finished our set and were packing up, one of the bloodied, swollen-eyed promoters claimed the milk urn they'd used to collect the gate had been pilfered during the embroglio and so they couldn't pay us. Being naive, I was prepared to believe him and just chock it up to the experiences of playing in a band. But our 2nd guitarist stepped in with a profanity-laden threat that if we didn't have our money by the time we were finished packing, the promoter's other eye was going to be fist-dotted much worse than the first.
Needless to say, we even got paid a bonus!