I have spent plenty of time in moshpits which resembled brawls and I've been in a few brawls that were more like square dances with people shouting curses at each other... but now I find myself in a new dilemma. I got involved in an 'altercation' in a parking lot after a show that my band played in. It was the usual drama of some dipshit following us out to the load-out after the show, drunk and talking shit and threatening us. There was pushing and shoving but no cops were called... and then the next day I have cops at my door, charging me with assualt. Since when does a guy go where he shoudn't, say stuff he shouldn't, START trouble and then call the cops the NEXT DAY? What the fuck is that about? ...and more importantly what now? - Defender.
Welcome to America, where no one will take personal responsibility for their own actions. I'm glad you didn't share too many details of the altercation in your letter because the first thing I would tell you is to Stop Talking About It. Don't go on-the-record with anyone describing what might or might not have happened. Next: Immediately find a lawyer. Seriously.
Things you probably have in your favor: The cops showed up the next day and (apparently) didn't drag you away in handcuffs... which means they probably already assume it is a BS charge... but don't depend on that (repeating: shut up and get a lawyer.) Also in your favor: It sounds like the guy acted alone and hopefully you have at least one or two bandmate/roadie witnesses. You'll also want to check with the venue - maybe they have security cameras in the parking lot? ...or maybe a neighboring business does... be proactive in looking for this stuff. Basically find as much proof as you can to tell your side of the story and then keep it to yourself - Wait and see what happens. If you threw the first actual punch, you might have some trouble. Let's hope that the dude, once he gets over his hangover and his embarrassment, just forgets the whole thing... but be ready in case he doesn't