Originally Posted by invader3k
I'd keep it simple and say something like, "Sorry, no, our band doesn't let other people sit in."
I had a woman at our last gig ask if she could get up on stage and sing with us. I just flat out said, "No, sorry." Maybe I'm just becoming less tolerant of people as I get older. The word "No", is a powerful one that you shouldn't be afraid to use.
This is how I (or we, in the case of the rest of the band) handle it.
I no longer offer explanations to these "players" who ask to sit in. "No", "Nope", or "Sorry, not happening" is what usually comes out of my mouth these days. Personally, I see it as a complete douchebag move to ask a band if you can get on stage with them.