How Woodwind Instruments Work

A flute, a clarinet, and a saxophone.

Woodwinds are one of the major families of instruments in use today. Woodwinds are basically defined as hollow tubes, which, when blown on one end, produce a sound. Most wind instruments have keys or fingerholes to vary the pitch of the sound, and different methods may be used to create the basic sound.

Mouthpieces

Single Reed (Clarinet/Saxophone)

The single reed produces a sound by vibrating against the mouthpeice when blown. The reed is held down by a metal ligature. Reeds are very sensitive, and must be cared for to produce the right tone.

Single reed mouthpiece

Double Reed (Oboe/Bassoon)

The double reed uses two reeds, tied together, to make a sound. The sound it produces is somewhat nasal, and can be very difficult to build, maintain, and play. Most double reed players make their own reeds. The tight opening of the double reed means that the musician can play long phrases in one breath.

double reed mouthpiece

Transverse Flute (Flute)

A transverse flute works by blowing air across a hole, much like blowing across a bottle makes a sound. It is one of the oldest ways to produce sound from a wind instrument. Transverse flutes are usually held horizontally.

Transverse flute mouthpiece

Whistle (Recorder)

The whistle is very similar to a transverse flute. Instead of a blowhole, air is blown into the end, past an opening further down the instrument, creating roughly the same effect.

Whistle mouthpiece

Playing Different Notes

Different notes are created by shortening or lengthening the air column inside the instrument. This is usually acheived by covering certain holes on the instument, either with keys or fingers.
The air column extends to the first open hole. Try this interactive diagram of a flute - click on the blowhole or keys to see how the air column and the pitch of the note is affected.