Ladies and gentlemen, I am a 69 year old amateur and play a Yamaha TR2330 with a Rudy Muck 17C mouthpiece.I have been playing for several years and have recently embarked on an effort to reduce mouthpiece pressure while playing. I ussually have 2 or 3, 30 minute practice sessions daily. My "comfort zone" is from C below the staff (C4) to D5. After about 6 - 10 minutes warming up (by playing major scales starting with C4) I can reach F5 or G5. On most days I can hit A5 and some rare days I can squeek out a momentary B5. After being able to hit G5 I consider the warmup over and I then play songs for the rest of the session. When I play songs that call for a lot of notes just above my comfort zone (F5 and G5), I feel a lactic acid burn in my jaw approximately around the rear molars of my upper jaw. I assume this a requisite step in extending my range. If I maximise my practice time playing songs that have a lot of notes above my comfort zone, I find fatigue and failure sets in quickly and I require a few minutes to recover. If on the other hand, I play songs that are in my comfort zone, I can play non stop for about 30-40 minutes with no more than about 5-10 seconds between songs (that last between 1 - 3 minutes). Would anyone care to comment on how to alter my sessions with the aim of extending my range? Thank you.