Which woodwind instrument has the most keys?

Answer 1

Bassoon!

Answer 2

Brass instruments use valves (usually three) to route air through longer sections of tubing, effectively making the tube longer and thus lowering the pitch. Using different combinations of valves it is possible to play seven fundamental tones (also called pedal tones) which have a wave length the entire length of the tube. Those seven, descending in half-steps are fingered: open; 2nd valve; 1st valve; 1st and 2nd or 3rd; 2nd and 3rd, 1st and 3rd, and all three.

Higher pitches on brass instruments are played using overtone partials. Causing the lips to vibrate faster results in a shorter wavelength which can only be sustained at exactly one-half, one third, one-forth, one fifth, etc. the length of the tube. In fact, the lowest practical notes on brass instruments are the first partial with wavelengths one half the length of the tube - an octave above the fundamental or pedal tone. The second partial (wavelength 1/3 the length of the tube) sounds and octave and a fifth above the fundamental. Since three valves provide seven pitches in a partial, all notes can be reached if we ignore the pedal tones.

Woodwind instruments also effectively lengthen the tube to play lower notes, but for determining wavelength, the tube is measured from the mouthpiece end to the highest open hole. Using keys, it is possible to achieve many more than seven pitches in a partial. A Flute or sax can reach more than a dozen notes, by half steps, in the lower octave. A Clarinet can reach twenty. Woodwinds also use higher partials by using a register key (called an octave key on flute or sax, since they reach the second partial - an octave above the fundamental). The fundamental is usable on woodwinds, and is the lower register. Saxes have additional keys which are used in the upper octave to shorten the tube and play higher notes, thus extending the range. Clarinets' register keys reach the third partial (the first partial is never used) and reach an even higher partial (the fifth), two octaves and a third above the fundamental for it's highest practical register. Skipping the second an fourth partial while adding enough keys to reach all of the pitches give the clarinet a large range - over three octaves.

Thus, brasses reach more partials, but play fewer pitches (and have fewer valves) per partial while woodwinds play more notes per partial (requiring more keys) but reach fewer partials.

Answer 3

clarinet