I woke up this morning with a horrible mouth ulcer right in the middle of the inside of my top lip. They are such a pain for flute playing and I usually wait them out with some tcp and put up with it, BUT, I am solo flute of my concert band and we have a really big concert tomorrow where I'm doing several solos. Does anyone have any quick fixes? Or advice on how to still make a good sound? It sounds so whispery especially anything above the C/D above the stave. I probably won't be able to get rid of it in time but any general tips on playing well despite this? Or for future, does anyone know of good quick cures?
Thanks!

Thank you, will that not numb the entire top lip though and affect flexibilty/embouchure? My problem isn't really the pain it's more of an obstruction to the air maybe or reducing flexibility? I don't know exactly why my sound has got this much worse though!
I will try the local anaestetic idea in the morning and if it works then use it in the evening.

You can do a couple of things to help it get a letter better. You can put cold milk on it. Soak a cotton ball in milk and kepp it on the cold sore. Licorice, real licorice, has some type of acid in it that helps promote healing. So get a real blakc licorice whip and keep it damp and near your sore.

DONT cover your core up with anything.

For future reference. Stay out of the sun or use good sun block on your lips when you go out in the sun to limit future breakouts. And if you get these often see your doctor and tell him or her. There are some diet guidelines that can help minimize the outbreaks and there are some new drugs out that might help curtail the number of outbreaks.