A band friend of mine extends his middle finger and says, "This one's free, but the next one's going to cost you!"
By the way, I play in an acoustic duo. We usually play "Locomotive Breath" acoustically, but aggressively, at our gigs. It is surprisingly well received, even by people who are unfamiliar with the original.
I’m in, on that last.
The closest I’ve ever come to getting arrested at a concert was at a Jethro Tull show. Long story, LOL. Ah, the memories of a (partially) misspent youth!