Ive had this problem which started about two weeks ago. I have found my standard of playing going downhill and play above top C's and above. - i am reasonable comfotable with my high range and this suddenlack of capability is getting worrying as i have a concert on Saturday. The reason, is that my lips have become sore and irritable whebn i play, they become a much deeper red and is quite painful. This reaction, im sure is nothing to do a lack of warming up before practise/taking on too much, as my practise routine hasn't changed and i do a good warm up! One of my friends said that it was a dodgy cold sore- but i've never had a cold sore! I asked my music teacher and he thinks i have had an allergic reaction to my mouthpiece. Here are my questions... Is this possible on a mouthpiece i have been using for 5 years? What kind of metal are mouthpieces made from? Does anyone know of any creams i can use to get my mouth back to normal? Will i have to get a new trumpet mouthpiece on top of this due to the same metal? If i am going to get a mouthpiece im gona make sure its a blimin good one! - what cornet mouthpieces do people use? I would really appreciate helpon this, i am completely lost!!