Well, to be sure, a clarinetist can change the pitch of the instrument, but there is a narrow window. If you lengthen or shorten the tube, all those nice little holes drilled at precise locations to produce note in tune, are now in the wrong places. By changing the length of the clarinet, in essence you have re-scaled the instrument. This holds true for all "fixed pitch" instruments, and the oboe, even more than the clarinet, is the one with the worst problem. A very short tube it is, and very cantankerous. This is why it is the instrument to which orchestras tune, not its unerring pitch. For what it is worth, pitch standards have varied widely over the years. Probably a conspiracy by oboe (and clarinet) makers to spur sales of new instruments. Steve P
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