Tone hole
Encyclopedia
A tone hole is an opening in the body of a wind instrument
which, when covered by a key
, alters the pitch of the sound produced.
The resonant frequencies
of the an air column in a pipe are inversely proportional to the pipe's effective length. For a pipe with no tone holes, the effective length is the physical length plus corrections for end effects. A shorter pipe, in other words, produces higher notes. An open hole in the side of the pipe shortens the pipe's effective length and therefore raises the pitch of the notes it produces. Generally a large hole in a given position reduces the effective length to something slightly larger than the effective length of a pipe cut off at that position; a smaller hole produces a longer effective length. Covering the hole with a finger, or with a pad operated by a key, increases the effective length and lowers the pitch again. However, a pipe with a closed tone hole is not acoustically identical to a pipe with no hole; the closed hole modifies the pipe's shape and its effective length.
When there are multiple toned holes, the first (highest) open toned hole usually has the largest influence on the pipe's effective length. However, closing holes below the first open hole can lower the pitch significantly; such cross fingerings may often be useful. Generally the pitch and timbre
of the notes produced will depend on the positions, sizes, heights, and shapes of all the tone holes, both open and closed. Theoretical models allow these effects to be calculated with some accuracy, but the design of tone holes remains to some degree a matter of trial and error.
Most woodwind instrument
s rely on tone holes to produce different notes; two exceptions are the slide whistle
and the willow flute
. Most brass instrument
s use valves or a slide instead of tone holes, with the rare keyed bugle
and the ophicleide
as exceptions.
Wind instrument
A wind instrument is a musical instrument that contains some type of resonator , in which a column of air is set into vibration by the player blowing into a mouthpiece set at the end of the resonator. The pitch of the vibration is determined by the length of the tube and by manual modifications of...
which, when covered by a key
Key (instrument)
A key is a specific part of a musical instrument. The purpose and function of the part in question depends on the instrument.On instruments equipped with tuning machines, violins and guitars, for example, a key is part of a tuning machine. It is a worm gear with a key shaped end used to turn a cog,...
, alters the pitch of the sound produced.
The resonant frequencies
Acoustic resonance
Acoustic resonance is the tendency of an acoustic system to absorb more energy when it is forced or driven at a frequency that matches one of its own natural frequencies of vibration than it does at other frequencies....
of the an air column in a pipe are inversely proportional to the pipe's effective length. For a pipe with no tone holes, the effective length is the physical length plus corrections for end effects. A shorter pipe, in other words, produces higher notes. An open hole in the side of the pipe shortens the pipe's effective length and therefore raises the pitch of the notes it produces. Generally a large hole in a given position reduces the effective length to something slightly larger than the effective length of a pipe cut off at that position; a smaller hole produces a longer effective length. Covering the hole with a finger, or with a pad operated by a key, increases the effective length and lowers the pitch again. However, a pipe with a closed tone hole is not acoustically identical to a pipe with no hole; the closed hole modifies the pipe's shape and its effective length.
When there are multiple toned holes, the first (highest) open toned hole usually has the largest influence on the pipe's effective length. However, closing holes below the first open hole can lower the pitch significantly; such cross fingerings may often be useful. Generally the pitch and timbre
Timbre
In music, timbre is the quality of a musical note or sound or tone that distinguishes different types of sound production, such as voices and musical instruments, such as string instruments, wind instruments, and percussion instruments. The physical characteristics of sound that determine the...
of the notes produced will depend on the positions, sizes, heights, and shapes of all the tone holes, both open and closed. Theoretical models allow these effects to be calculated with some accuracy, but the design of tone holes remains to some degree a matter of trial and error.
Most woodwind instrument
Woodwind instrument
A woodwind instrument is a musical instrument which produces sound when the player blows air against a sharp edge or through a reed, causing the air within its resonator to vibrate...
s rely on tone holes to produce different notes; two exceptions are the slide whistle
Slide whistle
A slide whistle is a wind instrument consisting of a fipple like a recorder's and a tube with a piston in it. Thus it has an air reed like some woodwinds, but varies the pitch with a slide. The construction is rather like a bicycle pump...
and the willow flute
Willow flute
The willow flute, also known as sallow flute , is a Scandinavian folk flute, or whistle, consisting of a simple tube with a transverse fipple mouthpiece and no finger holes...
. Most brass instrument
Brass instrument
A brass instrument is a musical instrument whose sound is produced by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips...
s use valves or a slide instead of tone holes, with the rare keyed bugle
Bugle (instrument)
The bugle is one of the simplest brass instruments, having no valves or other pitch-altering devices. All pitch control is done by varying the player's embouchure, since the bugle has no other mechanism for controlling pitch. Consequently, the bugle is limited to notes within the harmonic series...
and the ophicleide
Ophicleide
The ophicleide is a family of conical bore, brass keyed-bugles. It has a similar shape to the sudrophone.- History :The ophicleide was invented in 1817 and patented in 1821 by French instrument maker Jean Hilaire Asté as an extension to the keyed bugle or Royal Kent bugle family...
as exceptions.