Posted by Chuck Shorten on October 13, 1999 at 12:34:44:
I'm an amateur tuba player having some trouble with two areas:
1.  Mouthpiece Buzzing:  When I buzz I've always held my pinky finger part way over the outlet, thus providing some resistance to airflow and allowing for a more controllable sound.  The last time I attended a master class (by Dan Perantucci) he held the mouthpiece and buzzed without any restriction.  I don't see other players restricting the airflow either, yet when I buzz without the outlet covered somewhat it takes a LOT of air and I can't control it as well.  This doesn't appear to be an issue for smaller mouthpieces (euph/trumpet etc.)  Suggestions?
2.  When I play in the higher registers for more than a few notes my tone will often break on sustained notes.  Sometimes this happens as low as Eb in the staff.  I can best describe it as a deterioration of the sound - almost raspy and unpleasant - as opposed to clean and well-centered.  Sometimes just moving more air improves the sound quality.  The answer may just be "practice in the upper register more" but I wonder if anyone has any experience with this or suggestions for improvement here.
Thanks!