Vessel flute

Blowing across the opening of empty bottle produces a basic edge-blown vessel flute.

A referee's whistle is technically a fipple vessel flute, although it only plays one note.

They have no fipple and rely on the player's mouth to direct the air at an edge.

The shepherd's whistle is an unusual vessel flute; the fipple consists of two consecutive holes, and the player's mouth acts as a tunable vessel resonator.

A nose whistle also uses the mouth as a resonating cavity, and can therefore vary its pitch.

Sound is generated by oscillations in an airstream passing an edge, just as in other flutes.

[3] Some vessel flutes have a fipple to direct the air onto the labium edge, like a recorder.

Others rely on the player's lips to direct the air against the edge, like a concert flute.

The pitch of a vessel flute is affected by how hard the player blows.

Vessel flutes generally have no tuning mechanism, partly because they rely on variations in breath pressure and partly because the volume of the chamber and the size of the voicing need to be matched to produce a good tone.

Other things being equal, vessel flutes are louder when they use more air,[6] and when they are being played at higher pressures.

The resonant frequency of a vessel flute is given by this formula: (heavily simplified, see simplifications)[8]

It also means that, in theory, opening a specific hole on an instrument always raises the pitch by the same amount.

In practice, the pitch of a vessel flute is also affected by how hard the player blows.

[5] To compensate, fingering charts soon diverge from the plain binary progression.

[2] In similar instruments with a narrow cone shape, like the Gemshorn or Tonette, some partial overtones are available.

[citation needed] Some ocarinas are double- or triple-chambered, often with the chambers tuned an octave or a tenth apart.

The optimal air pressure can also be more consistent between notes (a flatter breath curve), making multichambers easier to play, especially for fast music with large jumps in pitch.

The ratio of pressure to air density in an ideal gas is constant.

Borrindos, vessel flutes made of clay, often by children.

Air pressure oscillating in the body of a vessel flute with no fipple. These are sounded by blowing across a hole, just like blowing across the opening of an empty bottle. In this case, the labium is the edge of the far side of the hole. Just as in a fipple flute, the airstream alternates quickly between the inner and outer side of the labium; another diagram, with fipple .