Somebody posted video of Eric Church stopping his show on Friday in Boston to break up a fight. He's pretty calm about it considering it started when "a drunk lady hit a teenager with her boot."
You don't see the fight, it's just Eric on stage issuing an ultimatum. He says, "No fighting, no fighting, no fighting. I don't sing if you fight, that's the way it goes. I don't sing if you fight." It's over in about a minute and he goes back to singing.
**WARNING there may be some swear words in this video**