From: "Dwight V. Bird" <dvbird@sisna.com>
Date: Tue, 22 Apr 1997 13:01:10 -0700
Subject: Re: fainting! Re: Plumbing 101
Just a comment on your (Paul Katula) comment regarding vibration of
the lips. I have often heard brass players say that they are
"reducing the vibrating area" when they tighten their embouchure.
I can only guess that the mental concept being used is something similar
to that of shortening a string on a violin. Although it may feel
this way to the performer, I don't believe that this is what is happening.
The natural frequency of a "thing" as described in vibration theory, is
proportional to the square root of a spring constant divided by the mass
of the thing. (w=(k/m)^.5). To play high we want the resonant frequency
of our lip to go up. According to the relation I just typed, one
can do this by decreasing the mass (making less lip), or increasing the
"spring constant".
What does this mean to us? The spring constant is roughly a measure
of stiffness. Unsupported flesh is flabby, flesh that is supported
by a flexed muscle is stiffer. Thus, it resonates at a higher frequency.
(Note also, that pushing hard with your trumpet against you face will compress
your lip. This compression stiffens it too. That is why the
trumpet "octave key" works. But try not to use it, as you can hurt
yourself.
Now, when your lip is stiffer, it becomes harder for the same volume of
air to get through. To get that air through, you have to increase
the AIR pressure. I was taught a long time ago that pressure was
a dirty word. Air pressure is not a dirty word. Air pressure
is generated by squeezing the air out of you lungs. Good trumpet
teachers teach us to increase the speed of the air in our mouth.
Guess how this is done. It
is done by increasing the air pressure in our lungs. There are more
and less efficient ways to do this. I believe that the concepts tough
by Arnold Jacobs and his students are very good.
In my case, the element that limits how high I can play, is the amount
of air pressure that I can create. My lips are capable of completely
closing off the air stream (meaning that they are plenty stiff to play
higher than I am able to play).
Enough of this. Who cares anyway, right? Just play!
- --
Dwight V. Bird
Mechanical/Environmental Engineer
EASE, Inc., Salt Lake City, Utah, USA
