Posted by Art H on February 13, 2003 at 00:26:23:
In Reply to: intonation repair posted by Dave on February 12, 2003 at 02:05:39:
To alter the pitch of one note on a brass instrument without affecting the other notes you would have to re-shape the entire bore, not just one section. For example, to raise the pitch of a certain note you would have to shrink the tubing slightly in the neighborhood of EVERY pressure antinode, and the constrictions would have to be roughly half a wavelength in length. Then to correct the next problem note you would have to do the same thing all over again with a different set of antinodes. Just finding the antinodes (or predicting their locations with a computer model) is a terribly difficult problem, compounded by the huge amount of taper in a tuba. Then you need to fabricate lots models to test your predictions and to learn from your mistakes. That gets to be very expensive. In spite of a lot of folk-legends and myths, there is no easier way to do it.