In music, the bore of a wind instrument (including woodwind and brass) is its interior chamber.
Other shapes are not generally used, as they tend to produce dissonant, anharmonic overtones and an unmusical sound.
Instruments may consist of a primarily conical or cylindrical tube, but begin in a mouthpiece, and end in a rapidly-expanding "flare" or "bell".
These modify the instrument's resonances to closely resemble that of a conical pipe, even if the bore is mostly cylindrical.
The wavelength produced by the second normal mode is approximately equal to the length of the cone, so its pitch is an octave higher.
The bore of a baroque recorder has a "reversed" taper, being wider at the head and narrower at the foot of the instrument.
The higher modes however do correspond fairly to integer multiples of a "fictitious fundamental" which can often still be played as a pedal tone.
[5] Players of brasses (in contrast to woodwinds) are able to "lip" notes up or down substantially, and on some instruments make use of privileged frequencies (pedal tones and false tones), to obtain in-tune notes outside of the range allowed for by the normal modes.