Guest singers--the thorn in the side of performers! My guest mic has no on/off switch. I mute it on the mixer. I've actually had people come onstage, pick it up and sing along the entire song without it being on. Only invited guests get to hear it in the p.a.! If someone tries to grab my personal mic, I will stop in the middle of a song if necessary. I told a guy one time, over the mic, that I didn't share my mic with anyone. He asked why, and I told him I was afraid that one of us might have a disease.
I've found that since (K-word) has gotten so popular that this is a bigger problem that ever. They sometimes don't even ask--just come up, even pick up a book off my music rack as if they own the place.
This reinforces my decision to concentrate on Nursing Homes.
Fact is, the customers don't mean any harm. They just wish they could do what we do, and I suppose we should be flattered. One of my most loyal "fans" owns a t.v. repair shop and, although he would like to be a singer, really can't carry a tune. I told him once that if he tried to sing with me again, I would get drunk the next morning, come to his shop and help him work on t.v.s. Fortunately, he laughed, but never tried to sing with me again.
DonM