Posted by Bill on December 16, 2000 at 10:04:25:
In Reply to: Re: Re: Re: More orchestral questions... posted by Aubrey Foard on December 15, 2000 at 23:32:00:
I am afraid have to side with you on this issue but it is not unreasonable to think of this as "dropping the jaw" if you think of dropping the hinge and not the front of the jaw. Since you can not drop the hinge, without dislocating the jaw, the result is to shift the flesh (tongue, soft tissue) farther apart and get not only your mouth but also your sinus cavities working on resonating the tone. Why this causes the tuba to resonate, I don't really know but it seems to work.
There is also a school of screech brass playing where you speed up the air's vibrations by squeezing it in this area and "condition" it for high notes. I don't know anything about this either except that it works for some people but not for me on tuba.