harold wrote:What many of us don't seem to realize is that most of what we are doing is ruled by the laws of physics. As such, we should be able to show scientifically that a change has taken place.
We've had this discussion so many times on the various trombone forums, I don't know if I can stand to do it again, but here goes.
The laws of physics are nothing more than descriptions of what actually happens. Physicists get better and better at describing and predicting, but their knowledge always reaches a limit. In the case of brass instruments, they really don't understand the entire system, and any physycist who has really studied it will admit that.
The fact, supported by an overwhelming amount of anecdotal evidence, is simply that changing aspects of a brass instrument, interior or exterior dimensions or weight or properties of materials, changes aspects of how the instrument sounds and responds to the player. That physicists don't completely understand why doesn't change that overwhelming evidence.
Bloke, in the case of the Bach open-wrap, we're not talking about a tiny brace, we're talking about the biggest brace on the instrument. It makes a BIG difference...and furthermore, small braces make a difference too.
One of the smartest people I know is a very good amateur horn player and a leading MIT physicist, who is devoting his retirement to studying the physics of brass instruments. His working theory at this point boils down to this: changes in materials and the distribution and amount of mass on an instrument of course don't change much about the vibrating air column
inside the horn, but they have profound effects on the feedback loop that involves the source of the vibration itself, the buzz.
In other words, the differences we're talking about in instrument design
directly affect the way your lips buzz. You have to be starting with good input from your brain and body, but the instrument itself, including how much mass there is at the mouthpiece and at other important parts of the instrument, and where and how heavy the braces are, and every other aspect of the physical properties of the instrument, contribute feedback to the input you are producing at your lips.
This rings true with my experience, and I think ultimately he will be proven correct.