Oh!... It just keeps getting better(?)....
My friend just called me about the concert he played tonight. First of all, the concert ended up starting about 40 minutes late, and the house staff eventually just ended up letting everyone who was still waiting to get into the hall without tickets in hand. -Which is probably what the should have done in the first place since most everyone was being comped.
It also turned out that their was a change in order of the pieces for tonight's concert. Of course, he didn't realize that until he was backstage and started hearing some "familiar" music. -And he had even checked with one of the stage managers beforehand to double-check the order for tonight's concert! Thankfully, he was able to sneak on stage and join the piece about a minute or two into it.
YIKES! and WHEW!