Wind instrument
Encyclopedia
A wind instrument is a musical instrument
that contains some type of resonator
(usually a tube), in which a column of air is set into vibration by the player blowing into (or over) 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 the effective length of the vibrating column of air. In the case of some wind instruments, sound is produced by blowing through a reed; others require buzzing into a metal mouthpiece.
All wind instruments use a combination of the first or second or third and the fourth method to extend their register.
Although brass instruments were originally made of brass and woodwind instruments have traditionally been made of wood, the material used to make the body of the instrument is not always a reliable guide to its family type. A more accurate way to determine whether an instrument is brass or woodwind is to examine how the player produces sound. In brass instruments, the player's lips vibrate, causing the air within the instrument to vibrate. In woodwind instruments the player either:
For example, the saxophone
is typically made of brass, but is classified as a woodwind instrument because it produces sound with a vibrating reed
.
On the other hand, the wooden cornett
(not to be confused with the cornet
, which is made of brass) and the serpent
are both made of wood (or plastic tubing, in the case of modern serpents), but belong to the family of brass instruments because the vibrating is done by the player's lips.
In the Hornbostel-Sachs
scheme of musical instrument classification
, wind instruments are classed as aerophone
s.
entry of air into a flow-control valve
attached to a resonant chamber (resonator
).
The resonator
is typically a long cylindrical or conical tube, open at the far end.
A pulse of high pressure from the valve will travel down the tube at the speed of sound
.
It will be reflected
from the open end as a return pulse of low pressure.
Under suitable conditions, the valve will reflect the pulse back, with increased energy,
until a standing wave
forms in the tube.
Reed instruments such as the clarinet
or oboe
have a flexible reed
or reeds
at the mouthpiece, forming a pressure-controlled valve.
An increase in pressure inside the chamber will decrease the pressure differential
across the reed; the reed will open more, increasing the flow of air.
The increased flow of air will increase the internal pressure further, so
a pulse of high pressure arriving at the mouthpiece will reflect
as a higher-pressure pulse back down the tube.
Standing wave
s inside the tube will be odd multiples of a quarter-wavelength
,
with a pressure anti-node
at the mouthpiece, and a pressure node
at the open end.
The reed vibrates at a rate determined by the resonator
.
For Lip Reed (brass
) instruments, the player controls the tension in their
lips so that they vibrate under the influence of the air flow through them.
They adjust the vibration so that the lips are most closed, and the air flow is lowest,
when a low-pressure pulse arrives at the mouthpiece,
to reflect a low-pressure pulse back down the tube.
Standing wave
s inside the tube will be odd multiples of a quarter-wavelength
,
with a pressure anti-node
at the mouthpiece, and a pressure node
at the open end.
For Air Reed (flute
and fipple
-flute) instruments, the flow of air over the
mouth of the instrument forms a flow-controlled valve.
Some of the air-stream flows into the instrument's mouth,
leading to an increase in internal pressure,
while some of the air-stream flows across the top of the mouth—through a Bernoulli effect
this reduces the pressure at the mouth, drawing air out of the mouth and leading
to a decrease in internal pressure.
When the pressure inside the chamber decreases, more of the air-stream will enter the mouth,
and less will flow across the top of the mouth.
A pulse of high pressure arriving at the mouth will direct more air across the top of the mouth;
this will decrease the internal pressure, and send a low-pressure pulse back down the tube.
A pulse of low pressure arriving at the mouth will draw more air into the mouth;
this will increase the internal pressure, and send a high-pressure pulse back down the tube.
Standing wave
s inside the tube will be multiples of a half-wavelength
,
with pressure node
s at both ends.
The air-stream across the mouth vibrates at a rate determined by the resonator
.
To a rough approximation, a tube of about 40 cm. will exhibit resonances near the following points:
In practice, however, obtaining a range of musically useful tones from a wind instrument depends
to a great extent on careful instrument design, and playing technique.
The bell of a wind instrument is the round, flared opening opposite the mouthpiece. It is found on horns, trumpets and many other kinds of instruments. On brass instruments, the acoustical coupling from the bore to the outside air occurs at the bell for all notes, and the shape of the bell optimizes this coupling. On woodwinds, most notes vent at the uppermost open tone holes; only the lowest notes of each register vent fully or partly at the bell, and the bell's function in this case is to improve the consistency in tone between these notes and the others.
Musical instrument
A musical instrument is a device created or adapted for the purpose of making musical sounds. In principle, any object that produces sound can serve as a musical instrument—it is through purpose that the object becomes a musical instrument. The history of musical instruments dates back to the...
that contains some type of resonator
Resonator
A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical...
(usually a tube), in which a column of air is set into vibration by the player blowing into (or over) a mouthpiece
Mouthpiece (woodwind)
The mouthpiece of a woodwind instrument is that part of the instrument which is placed partly in the player's mouth. Single-reed instruments, capped double-reed instruments, and fipple flutes have mouthpieces while exposed double-reed instruments and open flutes do not.-Single-reed instruments:On...
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 the effective length of the vibrating column of air. In the case of some wind instruments, sound is produced by blowing through a reed; others require buzzing into a metal mouthpiece.
Methods for obtaining different notes
- Changing the length of the vibrating air column by changing the effective length of the tube through opening or closing holes in the side of the tube. This can be done by covering the holes with fingers or pressing a keyKey (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,...
which then closes the hole. This method is used in nearly all woodwind instrumentWoodwind instrumentA 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. - Changing the length of the vibrating air column by changing the length of the tube through engaging valves (see rotary valveRotary valveA rotary valve is a type of valve in which the rotation of a passage or passages in a transverse plug regulates the flow of liquid or gas through the attached pipes. The common stopcock is the simplest form of rotary valve...
, piston valvePiston valveA piston valve is a device used to control the motion of a fluid along a tube or pipe by means of the linear motion of a piston within a chamber or cylinder.Examples of piston valves are:...
) which route the air through additional tubing, thereby increasing overall tube length, lowering the fundamental pitch. This method is used on nearly all brass instrumentBrass instrumentA 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. - Changing the length of the vibrating air column by lengthening and/or shortening the tube using a slidingSlide (wind instrument)A slide is a part of a wind instrument consisting of two pieces of tubing fitted one closely inside the other, and used to vary the overall length of the tube, and therefore the pitch of the instrument...
mechanism. This method is used on the tromboneTromboneThe trombone is a musical instrument in the brass family. Like all brass instruments, sound is produced when the player’s vibrating lips cause the air column inside the instrument to vibrate...
and the slide whistleSlide whistleA 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...
. - Making the column of air vibrate at different harmonics without changing the length of the column of air (see harmonic seriesHarmonic series (music)Pitched musical instruments are often based on an approximate harmonic oscillator such as a string or a column of air, which oscillates at numerous frequencies simultaneously. At these resonant frequencies, waves travel in both directions along the string or air column, reinforcing and canceling...
).
All wind instruments use a combination of the first or second or third and the fourth method to extend their register.
Types of wind instruments
Wind instruments are typically grouped into two families:- Brass instrumentBrass instrumentA 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 - Woodwind instrumentWoodwind instrumentA 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
Although brass instruments were originally made of brass and woodwind instruments have traditionally been made of wood, the material used to make the body of the instrument is not always a reliable guide to its family type. A more accurate way to determine whether an instrument is brass or woodwind is to examine how the player produces sound. In brass instruments, the player's lips vibrate, causing the air within the instrument to vibrate. In woodwind instruments the player either:
- causes a reedReed (instrument)A reed is a thin strip of material which vibrates to produce a sound on a musical instrument. The reeds of most Woodwind instruments are made from Arundo donax or synthetic material; tuned reeds are made of metal or synthetics.-Single reeds:Single reeds are used on the mouthpieces of clarinets...
to vibrate, which agitates the column of air (as in a clarinetClarinetThe clarinet is a musical instrument of woodwind type. The name derives from adding the suffix -et to the Italian word clarino , as the first clarinets had a strident tone similar to that of a trumpet. The instrument has an approximately cylindrical bore, and uses a single reed...
, oboeOboeThe oboe is a double reed musical instrument of the woodwind family. In English, prior to 1770, the instrument was called "hautbois" , "hoboy", or "French hoboy". The spelling "oboe" was adopted into English ca...
or dudukDudukThe duduk , traditionally known since antiquity as a Ծիրանափող is a traditional woodwind instrument indigenous to Armenia. Variations of it are popular in the Middle East and Central Asia...
) - blows against an edge or fippleFippleA fipple is a constricted mouthpiece common to many end-blown woodwind instruments, such as the tin whistle and the recorder. These instruments are known variously as fipple flutes, duct flutes, or tubular-ducted flutes.-How it works:...
(as in a recorderRecorderThe recorder is a woodwind musical instrument of the family known as fipple flutes or internal duct flutes—whistle-like instruments which include the tin whistle. The recorder is end-blown and the mouth of the instrument is constricted by a wooden plug, known as a block or fipple...
), or - blows across the edge of an open hole (as in a fluteFluteThe flute is a musical instrument of the woodwind family. Unlike woodwind instruments with reeds, a flute is an aerophone or reedless wind instrument that produces its sound from the flow of air across an opening...
).
For example, the saxophone
Saxophone
The saxophone is a conical-bore transposing musical instrument that is a member of the woodwind family. Saxophones are usually made of brass and played with a single-reed mouthpiece similar to that of the clarinet. The saxophone was invented by the Belgian instrument maker Adolphe Sax in 1846...
is typically made of brass, but is classified as a woodwind instrument because it produces sound with a vibrating reed
Reed (instrument)
A reed is a thin strip of material which vibrates to produce a sound on a musical instrument. The reeds of most Woodwind instruments are made from Arundo donax or synthetic material; tuned reeds are made of metal or synthetics.-Single reeds:Single reeds are used on the mouthpieces of clarinets...
.
On the other hand, the wooden cornett
Cornett
The cornett, cornetto or zink is an early wind instrument, dating from the Medieval, Renaissance and Baroque periods. It was used in what are now called alta capellas or wind ensembles. It is not to be confused with the trumpet-like instrument cornet.-Construction:There are three basic types of...
(not to be confused with the cornet
Cornet
The cornet is a brass instrument very similar to the trumpet, distinguished by its conical bore, compact shape, and mellower tone quality. The most common cornet is a transposing instrument in B. It is not related to the renaissance and early baroque cornett or cornetto.-History:The cornet was...
, which is made of brass) and the serpent
Serpent (instrument)
A serpent is a bass wind instrument, descended from the cornett, and a distant ancestor of the tuba, with a mouthpiece like a brass instrument but side holes like a woodwind. It is usually a long cone bent into a snakelike shape, hence the name. The serpent is closely related to the cornett,...
are both made of wood (or plastic tubing, in the case of modern serpents), but belong to the family of brass instruments because the vibrating is done by the player's lips.
In the Hornbostel-Sachs
Hornbostel-Sachs
Hornbostel–Sachs is a system of musical instrument classification devised by Erich Moritz von Hornbostel and Curt Sachs, and first published in the Zeitschrift für Ethnologie in 1914. An English translation was published in the Galpin Society Journal in 1961...
scheme of musical instrument classification
Musical instrument classification
At various times, and in various cultures, various schemes of musical instrument classification have been used.The most commonly used system in use in the west today divides instruments into string instruments, wind instruments and percussion instruments...
, wind instruments are classed as aerophone
Aerophone
An aerophone is any musical instrument which produces sound primarily by causing a body of air to vibrate, without the use of strings or membranes, and without the vibration of the instrument itself adding considerably to the sound...
s.
Physics of Sound Production
Sound production in all wind instruments depends on theentry of air into a flow-control valve
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...
attached to a resonant chamber (resonator
Resonator
A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical...
).
The resonator
Resonator
A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical...
is typically a long cylindrical or conical tube, open at the far end.
A pulse of high pressure from the valve will travel down the tube at the speed of sound
Speed of sound
The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at , the speed of sound is . This is , or about one kilometer in three seconds or approximately one mile in five seconds....
.
It will be reflected
Signal reflection
Signal reflection occurs when a signal is transmitted along a transmission medium, such as a copper cable or an optical fiber, some of the signal power may be reflected back to its origin rather than being carried all the way along the cable to the far end. This happens because imperfections in the...
from the open end as a return pulse of low pressure.
Under suitable conditions, the valve will reflect the pulse back, with increased energy,
until a standing wave
Standing wave
In physics, a standing wave – also known as a stationary wave – is a wave that remains in a constant position.This phenomenon can occur because the medium is moving in the opposite direction to the wave, or it can arise in a stationary medium as a result of interference between two waves traveling...
forms in the tube.
Reed instruments such as the clarinet
Clarinet
The clarinet is a musical instrument of woodwind type. The name derives from adding the suffix -et to the Italian word clarino , as the first clarinets had a strident tone similar to that of a trumpet. The instrument has an approximately cylindrical bore, and uses a single reed...
or oboe
Oboe
The oboe is a double reed musical instrument of the woodwind family. In English, prior to 1770, the instrument was called "hautbois" , "hoboy", or "French hoboy". The spelling "oboe" was adopted into English ca...
have a flexible reed
Reed (instrument)
A reed is a thin strip of material which vibrates to produce a sound on a musical instrument. The reeds of most Woodwind instruments are made from Arundo donax or synthetic material; tuned reeds are made of metal or synthetics.-Single reeds:Single reeds are used on the mouthpieces of clarinets...
or reeds
at the mouthpiece, forming a pressure-controlled valve.
An increase in pressure inside the chamber will decrease the pressure differential
across the reed; the reed will open more, increasing the flow of air.
The increased flow of air will increase the internal pressure further, so
a pulse of high pressure arriving at the mouthpiece will reflect
as a higher-pressure pulse back down the tube.
Standing wave
Standing wave
In physics, a standing wave – also known as a stationary wave – is a wave that remains in a constant position.This phenomenon can occur because the medium is moving in the opposite direction to the wave, or it can arise in a stationary medium as a result of interference between two waves traveling...
s inside the tube will be odd multiples of a quarter-wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
,
with a pressure anti-node
Node (physics)
A node is a point along a standing wave where the wave has minimal amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effective length of the vibrating string and thereby the...
at the mouthpiece, and a pressure node
Node (physics)
A node is a point along a standing wave where the wave has minimal amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effective length of the vibrating string and thereby the...
at the open end.
The reed vibrates at a rate determined by the resonator
Resonator
A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical...
.
For Lip Reed (brass
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...
) instruments, the player controls the tension in their
lips so that they vibrate under the influence of the air flow through them.
They adjust the vibration so that the lips are most closed, and the air flow is lowest,
when a low-pressure pulse arrives at the mouthpiece,
to reflect a low-pressure pulse back down the tube.
Standing wave
Standing wave
In physics, a standing wave – also known as a stationary wave – is a wave that remains in a constant position.This phenomenon can occur because the medium is moving in the opposite direction to the wave, or it can arise in a stationary medium as a result of interference between two waves traveling...
s inside the tube will be odd multiples of a quarter-wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
,
with a pressure anti-node
Node (physics)
A node is a point along a standing wave where the wave has minimal amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effective length of the vibrating string and thereby the...
at the mouthpiece, and a pressure node
Node (physics)
A node is a point along a standing wave where the wave has minimal amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effective length of the vibrating string and thereby the...
at the open end.
For Air Reed (flute
Flute
The flute is a musical instrument of the woodwind family. Unlike woodwind instruments with reeds, a flute is an aerophone or reedless wind instrument that produces its sound from the flow of air across an opening...
and fipple
Fipple
A fipple is a constricted mouthpiece common to many end-blown woodwind instruments, such as the tin whistle and the recorder. These instruments are known variously as fipple flutes, duct flutes, or tubular-ducted flutes.-How it works:...
-flute) instruments, the flow of air over the
mouth of the instrument forms a flow-controlled valve.
Some of the air-stream flows into the instrument's mouth,
leading to an increase in internal pressure,
while some of the air-stream flows across the top of the mouth—through a Bernoulli effect
Bernoulli's principle
In fluid dynamics, Bernoulli's principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy...
this reduces the pressure at the mouth, drawing air out of the mouth and leading
to a decrease in internal pressure.
When the pressure inside the chamber decreases, more of the air-stream will enter the mouth,
and less will flow across the top of the mouth.
A pulse of high pressure arriving at the mouth will direct more air across the top of the mouth;
this will decrease the internal pressure, and send a low-pressure pulse back down the tube.
A pulse of low pressure arriving at the mouth will draw more air into the mouth;
this will increase the internal pressure, and send a high-pressure pulse back down the tube.
Standing wave
Standing wave
In physics, a standing wave – also known as a stationary wave – is a wave that remains in a constant position.This phenomenon can occur because the medium is moving in the opposite direction to the wave, or it can arise in a stationary medium as a result of interference between two waves traveling...
s inside the tube will be multiples of a half-wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
,
with pressure node
Node (physics)
A node is a point along a standing wave where the wave has minimal amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effective length of the vibrating string and thereby the...
s at both ends.
The air-stream across the mouth vibrates at a rate determined by the resonator
Resonator
A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical...
.
To a rough approximation, a tube of about 40 cm. will exhibit resonances near the following points:
- For a reed or lip-reed instrument: 220 Hz (A3), 660 Hz (E5), 1100 Hz (C#6).
- For an air-reed instrument: 440 Hz (A4), 880 Hz (A5), 1320 Hz (E6).
In practice, however, obtaining a range of musically useful tones from a wind instrument depends
to a great extent on careful instrument design, and playing technique.
Parts