Guru,
Remember that when you are pissed 90% of the audience at a Folk Festival probably are aswell (especially at that time of day!) Therefore NOBODY will notice misteaks - and hey, we all make them, its how you deal with them that matters, my father in law always says a bum note is history, play on!
No we didn't have a beer, I was on H2O 'coz I was driving - so definately next time! I was the one on Saturday who sang Union Miners and The war to end all war (lost my voice by that stage - bloody hayfever!!)
Lucy