I have a group of women friends who play very tightly arranged and often gentle celtic pieces. They were booked to play for an hour at a fairly big gig (beer hall). Mid way through their 2nd to last song a man from the next act began to rearrange the stage around them. One couldn't bare it any longer so confronted him. He shoved her away....and she (involuntarily I understand) knee'd him. Suffice it say, he's rumoured to now only be able to play the piccolo.