I just got back from a show with my Getzen 300 Series and a Yamaha Bobby Shew Jazz Mouthpiece. The set ate me alive and it wasn't even that hard. We played seven tunes and I was playing lead - the lead parts put me usually either just above or just in the top of the staff. I was struggling to complete the third one, and then I started to sweat. The mouthpiece started to slip around on my face, and it lodged itself in a bad spot which strangled my range. I couldn't get it out of there cause it kept slipping back in because of the sweat. Anyways, I couldn't even pull out Gs on top of the staff. It only got worse from there. By the end of the set I wanted to pitch my horn out into the floor and walk out. The problem was that there was no reason for that kind of critical failure. It was unfortunate that it had to come for my end-of-year jazz band concert (Grade 11), but it's infuriating because there was no reason for it. I know I've played that exact set two times before, and each time I felt like I could have run the set again. But this time it just murdered me. It had no reason to murder me - I wasn't tired at the outset or anything like that. I'm feeling very frustrated and angry at the moment. Does anyone have any thoughts on why this might have happened or what would prevent it in the future?