What a jerk!

The general rule in the circles in which I've played is that whoever picks the song picks the key, tempo, and how long it lasts. We rarely sing so that's less of an issue, but if the person who called the song wants to sing, you do it his/her way or you shut up. You can do it your way when your turn comes.

I only had this happen once, and it wasn't nearly that bad. It was a particularly slow night at the local Irish session so the guy who was sort of leading the jam called me up to play, mic'ed, on my Appalachian dulcimer (which is, of course, not Irish, but the tune he asked me to play was a crowd favorite learned from another session regular, who had left his concertina at home that night but told me I was welcome to play "his" tune. I even play it in "his" key and tempo.) Session "leader" is an excellent bodhran player and played quietly behind me for a bit until one of the flute players decided this would be a good time to teach the guy next to him a completely different tune--on stage, mind you, about three feet away from my left elbow. Bodhran suddenly got a lot louder and "leader" gave the guy a look that would have curdled milk, which got the point across.