1 - my dog
i was invited up on stage to play when billy joel came to Gainesville and had a Q&A session....i got the chance to ask a question, and he invited me on stage to play. so i did! and it was f**king AWESOME!!!!!!!!!!!!!!!!!!! i think there were like 4,000 something people there...maybe more but i put the 3500 whateever one up there...
Hm... Unless you are severely underprepared - how does the number of people in a hall matter? When on stage - you are alone like a bug on a plate, but, if you have something important to share, you become the center figure and have no fear whatsoever. That's my experience as a performer, and a listener.
the biggest audience for you though must shurely have been at the cliburn, thousands in the hall(possibly), and thousands and thousands more at home watching on their computer.
6-7 hundred odd boys, + each boys parents.