I have many horns, but right now, I play a Euphonium (Adam E3 or Besson Prestige), a small-bore tenor trombone, and a bass trombone in 3 different bands. I play the small-bore trombone and Euphonium the same night (concert band and jazz band). For each, I use a different size mouthpiece. I find the Schilke 51D most comfortable for the Euphonium. I already own about 30 mouthpieces and need to stop experiencing. Does anyone have experience finding one mouthpiece (or size) that lends itself to all three horns similar to the 51D. Switching from small-bore trombone to Euphonium sometimes makes it difficult to find the high notes concisely. As I continue to play, maybe I will get better. I bought a Wessex Jazz Tuba and that is an altogether different story!