Posted by Rick Denney on January 14, 2003 at 16:56:56:
In Reply to: Re: Re: Re: Re: Re: Re: Re: Air posted by Tabor Fisher on January 13, 2003 at 19:01:54:
Here's how it works: A focused air-stream creates a tunnel of vacuum (this is the Bernoulli effect), which draw air from surrounding space and carries it along, too.
I can see how this would work for flutes, because the aperture is in free air and there is an amply supply of surrounding air to be pulled into the fast moving stream. I don't see how this helps a tuba player, because the mouthpiece is sealed from the surrounding air, and all the air that can be drawn into the stream comes from the same source (the player's lungs).
But I do think the notion of a focused air stream is an important concept--not because it physically draws more air into the instrument, but because it avoids the turbulence that keeps the air you do have from doing its job. Mike Sanders told me that we should focus the air in the mouthpiece as if to bring it to a sharp point about an inch downstream from the end of the mouthpiece shank. The visual he used was that of a well-adjusted torch flame.
Rick "who thinks Jacobs's trick could only work with a gap between his lips and the breathing bag" Denney