I was at a Don McLean concert in Reading, when a member of the audience rolled out of the first floor balcony, narrowly missed the huge bank of Bose speakers and landed just in front of the stage. D Mc was totally professional and carried on playing while the St John's ambulance folk carried him away.
I found out afterwards that the guy had had a tad too much to drink, needed to get to the loo and thought it would be quicker to try and climb from one balcony to the next, not realising there was a two-foot gap between them. He got away woth a broken collarbone.
There's a moral in there somewhere!