Depends on the venue and how recently you've seen your T or pdoc. The concert hall I perform in is huge so it only be chance if I ever saw him in the audience or outside the hall itself. I know my pdoc goes frequently and I've run into him only once, but it was no big deal. It was just by chance he had seats on the same level the chorus comes out from that performance. Otherwise I would never have known he was even there. I wouldn't presume to think he needs to warn me every time he attends a concert there. He doesn't know exactly what nights I'll be performing. It is his life, his ticket. He's the guest there, not me.