Hello everyone, I have been having some issues for a couple years now. I have terrible endurance problems, but my trumpet teacher and I have no idea whats wrong. I believe that the endurance problem is just a side effect of another problem. I know I do play a little bit in the red, but not much, that is until my mouthpiece starts slipping downward. It only happens when I play a G (the one just above the top ledger line) or higher. I also have some flexability issues that I believe are also side effects of the lip slippage. I know I dont have to be playing long for my cheeks to start burning like you wouldn't believe. I do practice regularly by the way. Has anyone had a similar problem?? I don't want to lose my ability to play the trumpet! I'm willing to work like a horse to fix it.