In the next two paragraphs, I�ve included some ideas from a recent post I�d like to address. My AP Physics class is taking their exam today, so I�ve got some rare free time!  I may regret this! :-)

>3-"It would be difficult, if not impossible, for the player to
>synchronize his/her lip opening by muscular action alone;
>fortunately, this is not necessary.  Pressure pulses reflected back
>from the horn tend to force the player's lips to open at the right
>time during the cycle of oscillation.

  > Translated...Reflected pressure pulses from the horn are necessary
>for the lips to oscillate steadily, because the player cannot
>physically produce or control the many discrete discrete puffs of air
>(440/second for a middle A) it would take to produce the note.

What is stated above is not a translation but an interpretation, and not a completely correct one, in my humble opinion.  Let me offer a different interpretation.

What Rossing is talking about here is resonance!  Feedback is required for resonance.  Whether or not anyone agrees or not cannot make that fact of nature go away.  Everyone one of you, whether or not you play trombone, trumpet, or flute are dealing with feedback. Enjoy it!  It�s why your horn works.  Let�s consider evidence for feedback.

1.)  Your lips can produce a continuum of notes, but there are no discrete slots.  It takes practice to learn how to buzz scales and you have to have �an ear�.  Let�s consider a trumpet with all of the valves up.  Can you play a continuum of notes!  Nope!  Well, you can�t do it and make all of the notes sound like a trumpet.  The notes available on a trumpet open horn are as follows:

Pedal C (very flat), Low C, G, C, E, G, B-flat (approximately), C, D, E, F-ish, G-ish, and so on.

Those notes are the notes you get BECAUSE OF FEEDBACK (a reflection from the bell barrier back to the mouthpiece at which there is another reflection and later an assist from a well placed puff of air, but I digress�).  These notes are the ones heard when standing waves form at those frequencies. Standing waves form because of feedback/reflections at the bell and the mouthpiece.

2.) Most of us speak of how well a horn slots.  The formal expression for this is �Q� (bandwidth divided by center frequency � correct me if I�m wrong here, John!! I�m flyin� without a net here!). This is another resonance phenomenon and resonance means FEEDBACK!

3.) The simple ability to buzz the lips doesn�t mean that it is easy to do. I will not quote statistics that I can�t pull up with proper documentation and I will not invent numbers that I can�t back up directly, so I will have to speak in generalities.  I have had quite a few people come to me for advice about chops.  They have come from all over the world.  They are interested what I have done that HAS WORKED FOR ME!  I walk them through my stuff, which includes a great deal about lip buzzing.  Most of these people were good players � not beginners.  You know what? Only a very few (one or two) really warmed up to my lip buzzing thing.  Many good players just can�t do it.  What�s the point?  When Rossing says or implies that "It would be difficult, if not impossible, for the player to synchronize his/her lip opening by muscular action alone� it has been my PROFESSIONAL EXPERIENCE that he isn�t wrong here!  One has to be VERY careful about interpreting or denigrating ideas without actually doing the study, and by study I mean, just going to a library and reading the book.

Now let�s go to the final point.  I�m going back to a discussion I had with Brad Goode a few years ago on a Barrett Deems gig at the Elbo Room in Chicago.  I was blowing lead and he was playing jazz (and wonderful jazz, I might add!  He�s an EXCELLENT musician � amazing versatility).  He insisted that his lips didn�t vibrate when he played.  To demonstrate this he played a G in the staff and held the shank of the mouthpiece and pulled it out of the horn while playing the note.  The note stopped almost as soon as the shank unsealed from the receiver.  He was insisting that the horn was absolutely necessary to even buzz and was questioning the efficacy of BERP practice, to say nothing of lip buzzing.  I then did the same demo, but as I pulled the mouthpiece out of my horn, the buzz never stopped!  I then pulled the mouthpiece away from my lips and still kept the buzz going.  Where does truth lie?  Somewhere in between.

You see, I was treating the lips as an acoustical driver.  That is exactly what I do with my practice routine.  A salpingonometer doesn�t flinch about playing some note on a trumpet electromechanically! It just plays!  If it is forced to play a non-resonant note, it may get warmer, but it still plays even between the slots when asked to.  But now let�s look at Brad�s position.

If you do what Brad did, and just keep the lips in the same position and not make any adjustments while playing and pulling the mouthpiece out of the horn, the tone WILL stop.  It does for me and I�ll bet it will for darn near everyone else. Now, no cheating here!  Do this without changing the aperture, tongue position, tension in the corners, anything!  The note will probably stop.

There was an excellent article about this by Thomas Moore in a discussion about this phenomenon as cited by Adams.  Moore tested the theory in his lab and found that it wasn�t difficult at all to reproduce Adam�s and Goode�s demo in the lab.  What is the connection?

I had trained myself to keep the lips buzzing in this removal process.  Like it or not, one has to make subtle adjustments to their embouchure.  It is a bit easier on trombone that it is on a trumpet because of the mouthpiece size, but those adjustments are there, nonetheless.  It is much harder to buzz the lips alone than to play them on a trumpet.  Did Rossing tell me that? Did Moore? Nope. It was Bobby Shew!  I was trying to learn how to use lip buzzing some 11 years ago, and I was failing miserably.  My playing was actually deteriorating a bit. I was working a weeklong gig with Shew and I bugged the heck out of him (Shoot! How often does one get to hang with a heavy like that?)!  I knew he was into buzzing, so I bounced my ideas around with him.  He asked about how long I buzzed.  I told him a half-hour to an hour a day.  He just about flipped.  He then pointed what should have been obvious to me as a reformed electrical engineer (;-)).  Without the help of the horn, I was simply wearing out my chops because it is so much harder to do this without the FEEDBACK (resonance).  When I cut back to 5 to 10 minutes a day, it started to come together for me.  Now, Shew is NOT a physicist or a scientist, but he has read a great deal of scientific literature and used those ideas in his playing.  Now, where I come from Shew IS a world-class player and he didn�t flinch at the physics or anatomy.

Now let me close this ridiculously long post!  The Moore findings (if memory serves, I don�t have them with me right now), published in the ITG, were that there were very tiny vibrations between the lips of a random hissing nature that were almost inaudible in the Adams/Goode demo.  Because the horns REALLY DO RESONATE (because of feedback), it doesn�t take much energy for a standing wave to build up.  In all noise there is a great deal of harmonic content.  If one of those frequencies happens to be a resonant frequency of the horn, a standing wave will quickly build up at that frequency and �capture the system� and the lips will then begin to go into a slight but full-fledged vibration.  What resonance means to us as trumpeters is that it doesn�t take a whole lot of energy to just get a note going on the horn because of resonance.

Now, I would love to hear from John Lynch on this.  I�m just a high school physics teacher (day gig) and trumpeter (night gig).  John is much better at all of this than I am.  Also, Chris Stratton once lit me up pretty good when I made some brash and incorrect statements.  He was quite right in his discussion (I think Ole Utnes has that darn exchange archived, I�m embarrassed to admit).  I would love Chris� input if he were tuned in. I hate to tackle these ideas alone here!

Now I�ll bet dollars to doughnuts that I�ve missed something here and I�m going to regret it!  But I have just used 80 minutes in trying to think this through, so, for the moment I�m going with it! Besides, this is already too long!

Getting my fire extinguisher ready!

Peace.

ND
http://www.mp3.com/NickDrozdoff