Resonant cavities have particular frequencies which resonate. Only small fraction of power of wave in pipe is reradiated/cycle. Length of pipe = wavelength.

For a pipe with a closed end, .

For a clarinet, so expect modes to be . It is actually 147Hz.

To get rid of the 1st mode, open a node of the way down the pipe. The first mode will radiate all of it's power away, but the second mode will be left intact.

source psfile jl@crush.caltech.edu index