Posted by Greg Crider on August 31, 2001 at 10:10:09:
In Reply to: CC 2 feet shorter??? posted by Steve Inman on August 31, 2001 at 09:52:10:
The primary tubing is what matters. The primary tubing is around 12% shorter in a CC horn than in a BB horn, and all of the valve tubings are proportionally shorter to match.
Another way to look at using more tubing to play a higher note is this: when you use 1st and third valve (or 4th), you are actually changing the key of the tuba. On a BBb horn, this would put the horn in FFF below BBb. If you play a C above the low Bb, you are using more tubing, but you are blowing the note from a higher partial in the horn's harmonic series, which is why you can get a higher pitch with more tubing. However, in determining the key of an instrument, only the primary (open) tubing counts. The various valve combinations are transient, so they're not counted.