Jon, you make a good point and I understand where you're coming from. If I was on stage and someone (even a jerk) REALLY wanted to play, I'd simplify what I was doing, or even change the songs I had planned. Easy for me to do (even though I'd rather tell jerks to go fuck themselves) 'cause I play solo and have a ton of experience at improvising....plus....THE AUDIENCE DOESN'T AND SHOULDN'T KNOW ABOUT THE FRICTION GOING ON,(sorry Susan, I shout so little, just thought I'd do it for fun)....but Tarheel and his wife sound like they have a "rehearsed show", so someone playing badly along with them would probably result in them looking bad.

Most jams I know DON'T have sound systems though, so I suspect this is a little more formal situation.

Rick