I was finding that with my regular mouthpiece (Denis Wick MM2C) I could not play upper register for any length of time despite efforts in practice. After reading an article (a Phd thesis - August Haas, The Art of Playing Trumpet in the Upper Register, Uni.of Miami), I thought I would look into trying out a couple of mouthpieces.
They are definitley a personal think - no one fits all.
This mouthpiece really helps me in the upper register, but I am struggling to play down low (A down to F#), but hoping that this will improve with practice.
I can not achieve the same power in the middle range as with the MM2C, and the sound is different (less mellow).
I got a Bobby Shew Lead mouthpiece at the same time, but am finding it harder to control than the Allen Vizzutti.
Still needs more time.
Guess it will be a matter of selecting which mouthpiece to use for different pieces.
Is this what professionals do?