Will is right - practice is vital but…stage fright is more than being nervous. I had a bizarre situation a couple of weeks ago where my fingers, instead of going automatically to the chord I'd played in the last line of the song, suddenly went 'blank'. I was left high and dry accompanying two singers and nowhere to go. Now I have developed number of strategies to deal with this…because I know its going to happen! There's the first trick - rehearse for stage fright situations! The other certainty on this thread, from my experience is Bert's brilliant observation. Laughter kills stage-fright dead!