I’ve been fortunate to have never had a band situation degenerate into onstage fisticuffs, but I did have a local/regional band utterly melt down mid-set in front of a hometown crowd back in mid-2000. The singer and guitarist got into a very heated argument, on mic; it never came to blows, but it was very close. We managed to finish the set, loaded our gear out, and scattered to the four corners, and that was the last time we played together as a band. Eventually the singer reconstituted the band with new personnel a couple of years later, but by that time the drummer and I had already moved on to Disarray and were gleefully touring the country.
I, of course, don’t count the time I offered personal violence to that same drummer in an Auto Zone parking lot an hour outside of Chicago (ie standing outside the van begging him to get out and get killed) after he left my keys (van keys, my car keys, and the keys to my house in TN) at his uncle’s house on the other side of town. Hey, at least we weren’t onstage.
Back to the OP. Get that guy out of your band, or else get yourself out. Quickly and publicly, and without either rancor or ambiguity, but get some distance. Even if you weren’t directly involved in the incident, you could be found guilty by association along with everyone else on stage. Even if, by some miracle, some of the crowd weren’t paying attention, I’ll guarantee that the club owner or his/her designate were, and if they share info with other area clubs, you could soon find yourself and/or your band labeled as radioactive. I’ve seen it happen. Not worth it.
