music Music is the arrangement of sound to create some combination of Musical form, form, harmony, melody, rhythm, or otherwise Musical expression, expressive content. Music is generally agreed to be a cultural universal that is present in all hum ...

, the bore of a

wind instrument 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 or near the end of the resonator. The pitch ...

(including

woodwind Woodwind instruments are a family of musical instruments within the greater category of wind instruments. Common examples include flute, clarinet, oboe, bassoon, and saxophone. There are two main types of woodwind instruments: flutes and Ree ...

and

brass Brass is an alloy of copper and zinc, in proportions which can be varied to achieve different colours and mechanical, electrical, acoustic and chemical properties, but copper typically has the larger proportion, generally copper and zinc. I ...

) is its interior chamber. This defines a flow path through which air travels, which is set into

vibration Vibration () is a mechanical phenomenon whereby oscillations occur about an equilibrium point. Vibration may be deterministic if the oscillations can be characterised precisely (e.g. the periodic motion of a pendulum), or random if the os ...

to produce sounds. The shape of the bore has a strong influence on the instrument's

timbre In music, timbre (), also known as tone color or tone quality (from psychoacoustics), is the perceived sound of a musical note, sound or tone. Timbre distinguishes sounds according to their source, such as choir voices and musical instrument ...

Bore shapes

The

cone In geometry, a cone is a three-dimensional figure that tapers smoothly from a flat base (typically a circle) to a point not contained in the base, called the '' apex'' or '' vertex''. A cone is formed by a set of line segments, half-lines ...

and the

cylinder A cylinder () has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infinite ...

are the two idealized shapes used to describe the bores of

s. Other shapes are not generally used, as they tend to produce dissonant, anharmonic

overtones An overtone is any resonant frequency above the fundamental frequency of a sound. (An overtone may or may not be a harmonic) In other words, overtones are all pitches higher than the lowest pitch within an individual sound; the fundamental i ...

and an unmusical sound. Instruments may consist of a primarily conical or cylindrical tube, but begin in a mouthpiece, and end in a rapidly-expanding "flare" or "

bell A bell /ˈbɛl/ () is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be m ...

". This flare reduces the

acoustic impedance Acoustic impedance and specific acoustic impedance are measures of the opposition that a system presents to the acoustic flow resulting from an acoustic pressure applied to the system. The International System of Units, SI unit of acoustic impeda ...

mismatch between the instrument and the air, allowing the instrument to transmit sound to the air more effectively. These shapes affect the prominence of

harmonics In physics, acoustics, and telecommunications, a harmonic is a sinusoidal wave with a frequency that is a positive integer multiple of the ''fundamental frequency'' of a periodic signal. The fundamental frequency is also called the ''1st harm ...

associated with the timbre of the instrument. A bore that flares from the mouthpiece reduces resistance to the breath, while a bore that narrows from the mouth increases it, compared to a cylinder.

Cylindrical bore

The diameter of a cylindrical bore remains constant along its length. The acoustic behavior depends on whether the instrument is ''stopped'' (closed at one end and open at the other), or ''open'' (at both ends). For an open pipe, the

wavelength In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...

produced by the first

normal mode A normal mode of a dynamical system is a pattern of motion in which all parts of the system move sinusoidally with the same frequency and with a fixed phase relation. The free motion described by the normal modes takes place at fixed frequencies ...

(the fundamental note) is approximately twice the length of the pipe. The wavelength produced by the second

is half that, that is, the length of the pipe, so its pitch is an

octave In music, an octave (: eighth) or perfect octave (sometimes called the diapason) is an interval between two notes, one having twice the frequency of vibration of the other. The octave relationship is a natural phenomenon that has been referr ...

higher; thus an open cylindrical bore instrument overblows at the octave. This corresponds to the second

harmonic In physics, acoustics, and telecommunications, a harmonic is a sinusoidal wave with a frequency that is a positive integer multiple of the ''fundamental frequency'' of a periodic signal. The fundamental frequency is also called the ''1st har ...

, and generally the harmonic spectrum of an open cylindrical bore instrument is strong in both even and odd harmonics. For a stopped pipe, the wavelength produced by the first normal mode is approximately four times the length of the pipe. The wavelength produced by the second normal mode is one third that, i.e. the 4/3 length of the pipe, so its pitch is a twelfth higher; a stopped cylindrical bore instrument overblows at the twelfth. This corresponds to the third harmonic; generally the harmonic spectrum of a stopped cylindrical bore instrument, particularly in its bottom register, is strong in the odd harmonics only. Modern brass instruments however generally make use of the full length of the instrument for every pitch, and are therefore significantly affected by the effects of the mouthpiece and

. These modify the instrument's resonances to closely resemble that of a conical pipe, even if the bore is mostly cylindrical. Instruments having a cylindrical, or mostly cylindrical, bore include: * Chalumeau *

Clarinet The clarinet is a Single-reed instrument, single-reed musical instrument in the woodwind family, with a nearly cylindrical bore (wind instruments), bore and a flared bell. Clarinets comprise a Family (musical instruments), family of instrume ...

Cornamuse The cornamuse is a double reed instrument dating from the Renaissance music, Renaissance period.Boydell, Barra R. "Cornamusa (i)." Grove Music Online. 2001. Oxford University Press. Date of access 8 Feb. 2024 It is similar to the crumhorn in ha ...

Crumhorn The crumhorn is a double reed , double reed instrument of the woodwind family, most commonly used during the Renaissance music, Renaissance period. In modern times, particularly since the 1960s, there has been a revival of interest in early mu ...

Flute The flute is a member of a family of musical instruments in the woodwind group. Like all woodwinds, flutes are aerophones, producing sound with a vibrating column of air. Flutes produce sound when the player's air flows across an opening. In th ...

( Boehm system — open) * Recorder (renaissance and some modern recorders) * Kortholt * Rackett (renaissance) *

Trumpet The trumpet is a brass instrument commonly used in classical and jazz musical ensemble, ensembles. The trumpet group ranges from the piccolo trumpet—with the highest Register (music), register in the brass family—to the bass trumpet, pitche ...

Trombone The trombone (, Italian, French: ''trombone'') is a musical instrument in the Brass instrument, brass family. As with all brass instruments, sound is produced when the player's lips vibrate inside a mouthpiece, causing the Standing wave, air c ...

Conical bore

The diameter of a conical bore varies linearly with distance from the end of the instrument. A complete conical bore would begin at zero diameter—the cone's vertex. However, actual instrument bores approximate a

frustum In geometry, a ; (: frusta or frustums) is the portion of a polyhedron, solid (normally a pyramid (geometry), pyramid or a cone (geometry), cone) that lies between two parallel planes cutting the solid. In the case of a pyramid, the base faces a ...

of a cone. The wavelength produced by the first normal mode is approximately twice the length of the cone measured from the vertex. The wavelength produced by the second normal mode is approximately equal to the length of the cone, so its pitch is an octave higher. Therefore, a conical bore instrument, like one with an open cylindrical bore, overblows at the octave and generally has a harmonic spectrum strong in both even and odd harmonics. Instruments having a conical, or approximately conical, bore include: * Alphorn *

Bassoon The bassoon is a musical instrument in the woodwind family, which plays in the tenor and bass ranges. It is composed of six pieces, and is usually made of wood. It is known for its distinctive tone color, wide range, versatility, and virtuosity ...

Conch shell Conch ( , , ) is a common name of a number of different medium-to-large-sized sea snails. Conch shells typically have a high spire and a noticeable siphonal canal (in other words, the shell comes to a noticeable point on both ends). Conchs ...

Cornet The cornet (, ) is a brass instrument similar to the trumpet but distinguished from it by its conical bore, more compact shape, and mellower tone quality. The most common cornet is a transposing instrument in B. There is also a soprano cor ...

Dulcian The dulcian is a Renaissance woodwind instrument, with a double reed and a folded conical bore. Equivalent terms include , , , , , , and . The predecessor of the modern bassoon, it flourished between 1550 and 1700, but was probably invented ...

Euphonium The euphonium ( ; ; ) is a tenor- and baritone-voiced valved brass instrument. The euphonium is a member of the large family of valved bugles, along with the tuba and flugelhorn, characterised by a wide conical bore. Most instruments have thr ...

Flugelhorn The flugelhorn (), also spelled fluegelhorn, flugel horn, or flügelhorn, is a brass instrument that resembles the trumpet and cornet, but has a wider, more conical bore. Like trumpets and cornets, most flugelhorns are pitched in B♭, though ...

(pre-Boehm) *

French Horn The French horn (since the 1930s known simply as the horn in professional music circles) is a brass instrument made of tubing wrapped into a coil with a flared bell. The double horn in F/B (technically a variety of German horn) is the horn most o ...

* Recorder (baroque and most contemporary recorders) *

Oboe The oboe ( ) is a type of double-reed woodwind instrument. Oboes are usually made of wood, but may also be made of synthetic materials, such as plastic, resin, or hybrid composites. The most common type of oboe, the soprano oboe pitched in C, ...

* Rackett (baroque) *

Rauschpfeife A rauschpfeife ( pl. rauschpfeifes or rauschpfeifen; German: Rauschpfeife, pl. Rauschpfeifen) is a capped conical reed musical instrument of the woodwind family, used in Europe in the 16th and 17th centuries. In common with the crumhorn and c ...

Saxhorn The saxhorn is a family of valved brass instruments that have conical bores and deep cup-shaped mouthpieces. The saxhorn family was developed by Adolphe Sax, who is also known for creating the saxophone family. The sound of the saxhorn has a ...

Saxophone The saxophone (often referred to colloquially as the sax) is a type of single-reed woodwind instrument with a conical body, usually made of brass. As with all single-reed instruments, sound is produced when a reed on a mouthpiece vibrates to p ...

Shawm The shawm () is a Bore (wind instruments)#Conical bore, conical bore, double-reed woodwind instrument made in Europe from the 13th or possibly 12th century to the present day. It achieved its peak of popularity during the medieval and Renaissanc ...

* Trembita *

Tuba The tuba (; ) is the largest and lowest-pitched musical instrument in the brass instrument, brass family. As with all brass instruments, the sound is produced by lip vibrationa buzzinto a mouthpiece (brass), mouthpiece. It first appeared in th ...

Uilleann pipes The uilleann pipes ( or , ), also known as Union pipes and sometimes called Irish pipes, are the characteristic national bagpipe of Ireland. Their current name is a partial translation of the Irish language terms (literally, "pipes of the ...

Woodwinds

Sections of the bores of

woodwind instrument Woodwind instruments are a family of musical instruments within the greater category of wind instruments. Common examples include flute, clarinet, oboe, bassoon, and saxophone. There are two main types of woodwind instruments: flutes and ...

s deviate from a true cone or a cylinder. For example, although

oboe The oboe ( ) is a type of double-reed woodwind instrument. Oboes are usually made of wood, but may also be made of synthetic materials, such as plastic, resin, or hybrid composites. The most common type of oboe, the soprano oboe pitched in C, ...

s and oboes d'amore are similarly pitched, they have differently shaped terminal bells. Accordingly, the voice of the oboe is described as "piercing" as compared to the more "full" voice of the oboe d'amore. Although the bore shape of woodwind instruments generally determines their timbre, the instruments' exterior geometry typically has little effect on their voice. In addition, the exterior shape of woodwind instruments may not overtly match the shape of their bores. For example, while oboes and clarinets may outwardly appear similar, oboes have a conical bore while clarinets have a cylindrical bore. The bore of a

baroque The Baroque ( , , ) is a Western Style (visual arts), style of Baroque architecture, architecture, Baroque music, music, Baroque dance, dance, Baroque painting, painting, Baroque sculpture, sculpture, poetry, and other arts that flourished from ...

recorder has a "reversed" taper, being wider at the head and narrower at the foot of the instrument. Most contemporary recorders also have such a conical bore as they are made very similar to baroque recorders. However, multiple

renaissance The Renaissance ( , ) is a Periodization, period of history and a European cultural movement covering the 15th and 16th centuries. It marked the transition from the Middle Ages to modernity and was characterized by an effort to revive and sur ...

medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of World history (field), global history. It began with the fall of the West ...

and also modern recorders have a

cylindrical A cylinder () has traditionally been a Solid geometry, three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a Prism (geometry), prism with a circle as its base. A cylinder may ...

bore. Some tin flageolets also have a reverse taper.

Brasses

Brass instrument A brass instrument is a musical instrument that produces sound by Sympathetic resonance, sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips. The term ''labrosone'', from Latin elements meani ...

s also are sometimes categorized as conical or cylindrical, though most in fact have cylindrical sections between a conical section (the mouthpiece taper or leadpipe) and a non-conical, non-cylindrical flaring section (the bell). Benade gives the following typical proportions: These proportions vary as valves or slides are operated; the above numbers are for instruments with the valves open or the slide fully in. This deviation from standard models of cylindrical and conical tubes means normal mode frequencies of brass instruments do not correspond to integer multiples of the first mode, which is not used for playing. The higher modes however do correspond fairly to integer multiples of a "fictitious fundamental" which can often still be played as a

pedal tone Pedal tones (or pedals) are special low notes in the harmonic series of brass instruments. A pedal tone has the pitch of its harmonic series' fundamental tone. Its name comes from the foot pedal keyboard pedals of a pipe organ, which are used ...

. Players of brasses (in contrast to woodwinds) are able to "lip" notes up or down substantially, and on some instruments make use of privileged frequencies (pedal tones and false tones), to obtain in-tune notes outside of the range allowed for by the normal modes.

Bore shapes

Cylindrical bore

Conical bore

Woodwinds

Brasses

See also

Sources

Further reading