music Music is generally defined as the art of arranging sound to create some combination of form, harmony, melody, rhythm or otherwise expressive content. Exact definitions of music vary considerably around the world, though it is an aspe ...

, 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 pitc ...

(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 re ...

and

brass Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other wit ...

) 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. The word comes from Latin ''vibrationem'' ("shaking, brandishing"). The oscillations may be periodic, such as the motion of a pendulum—or random, su ...

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 quality of a musical note, sound or tone. Timbre distinguishes different types of sound production, such as choir voices and musica ...

Bore shapes

The

cone A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines con ...

and the

cylinder A cylinder (from ) 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 infin ...

are the two idealized shapes used to describe the bores of

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

dissonant In music, consonance and dissonance are categorizations of simultaneous or successive Sound, sounds. Within the Western tradition, some listeners associate consonance with sweetness, pleasantness, and acceptability, and dissonance with harshness ...

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

bell A bell 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 made by an inte ...

". 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 SI unit of acoustic impedance is the pascal-second per cu ...

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 A harmonic is a wave with a frequency that is a positive integer multiple of the '' fundamental frequency'', the frequency of the original periodic signal, such as a sinusoidal wave. The original signal is also called the ''1st harmonic'', ...

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 produced by the first normal mode (the

fundamental Fundamental may refer to: * Foundation of reality * Fundamental frequency, as in music or phonetics, often referred to as simply a "fundamental" * Fundamentalism, the belief in, and usually the strict adherence to, the simple or "fundamental" idea ...

note) is approximately twice the length of the pipe. The wavelength produced by the second normal mode is half that, that is, the length of the pipe, so its pitch is an octave higher; thus an open cylindrical bore instrument overblows at the octave. This corresponds to the second harmonic, 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 The chalumeau (; ; plural chalumeaux) is a single-reed woodwind instrument of the late baroque and early classical eras. The chalumeau is a folk instrument that is the predecessor to the modern-day clarinet. It has a cylindrical bore with ei ...

* Clarinet *

Cornamuse The cornamuse is a double reed instrument dating from the Renaissance period. It is similar to the crumhorn The crumhorn is a double reed instrument of the woodwind family, most commonly used during the Renaissance period. In modern time ...

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

* Flute (

Boehm system The Boehm system is a system of keywork for the flute, created by inventor and flautist Theobald Boehm between 1831 and 1847. History Immediately prior to the development of the Boehm system, flutes were most commonly made of wood, with an ...

— open) *

Recorder Recorder or The Recorder may refer to: Newspapers * ''Indianapolis Recorder'', a weekly newspaper * ''The Recorder'' (Massachusetts newspaper), a daily newspaper published in Greenfield, Massachusetts, US * ''The Recorder'' (Port Pirie), a news ...

(renaissance and some modern recorders) *

Kortholt The kortholt is a musical instrument of the woodwind family, used in the Renaissance period. The name comes from Low Saxon and means short (''kort'') piece of wood (''holt''). This name is mentioned in the work ''Syntagma musicum'' by Michael ...

Rackett The rackett, raggett, cervelas, or sausage bassoon is a Renaissance-era double reed wind instrument, introduced late in the sixteenth century and already superseded by bassoons at the end of the seventeenth century. Description There are fou ...

(renaissance) *

Trumpet The trumpet is a brass instrument commonly used in classical and jazz ensembles. The trumpet group ranges from the piccolo trumpet—with the highest register in the brass family—to the bass trumpet, pitched one octave below the standard ...

Trombone The trombone (german: Posaune, Italian, French: ''trombone'') is a musical instrument in the brass family. As with all brass instruments, sound is produced when the player's vibrating lips cause the air column inside the instrument to vibrate ...

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 (from the Latin for "morsel"; plural: ''frusta'' or ''frustums'') is the portion of a solid (normally a pyramid or a cone) that lies between two parallel planes cutting this solid. In the case of a pyramid, the base faces are ...

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 The alphorn or alpenhorn or alpine horn is a labrophone, consisting of a straight several-meter-long wooden natural horn of conical bore, with a wooden cup-shaped mouthpiece. Traditionally the Alphorn was made of one single piece, or two par ...

* Bassoon *

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 at both ends). In North Ame ...

* Cornet *

Dulcian The dulcian is a Renaissance woodwind instrument, with a double reed and a folded conical bore. Equivalent terms include en, curtal, german: Dulzian, french: douçaine, nl, dulciaan, it, dulciana, es, bajón, and pt, baixão. The predeces ...

Euphonium The euphonium is a medium-sized, 3 or 4-valve, often compensating, conical-bore, tenor-voiced brass instrument that derives its name from the Ancient Greek word ''euphōnos'', meaning "well-sounding" or "sweet-voiced" ( ''eu'' means "well" o ...

* Flugelhorn * Flute (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 ...

(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 oboe plays in the treble or soprano range. ...

(baroque) *

Rauschpfeife Rauschpfeife is a commonly used term for a specific type of capped conical reed musical instrument of the woodwind family, used in Europe in the 16th and 17th centuries. In common with the crumhorn and cornamuse, it is a wooden double-reed inst ...

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 instrument, single-reed woodwind instrument with a conical body, usually made of brass. As with all single-reed instruments, sound is produced when a reed (mouthpi ...

Shawm The shawm () is a conical bore, double-reed woodwind instrument made in Europe from the 12th century to the present day. It achieved its peak of popularity during the medieval and Renaissance periods, after which it was gradually eclipsed by th ...

Tuba The tuba (; ) is the lowest-pitched musical instrument in the brass family. As with all brass instruments, the sound is produced by lip vibrationa buzzinto a mouthpiece. It first appeared in the mid-19th century, making it one of the ne ...

Uilleann pipes The uilleann pipes ( or , ) are the characteristic national bagpipe of Ireland. Earlier known in English as "union pipes", their current name is a partial translation of the Irish language terms (literally, "pipes of the elbow"), from thei ...

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 r ...

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 oboe plays in the treble or soprano range. ...

s and

oboes d'amore The oboe d'amore (; Italian for "oboe of love"), less commonly , is a double reed woodwind musical instrument in the oboe family. Slightly larger than the oboe, it has a less assertive and a more tranquil and serene tone, and is considered the ...

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

recorder Recorder or The Recorder may refer to: Newspapers * ''Indianapolis Recorder'', a weekly newspaper * ''The Recorder'' (Massachusetts newspaper), a daily newspaper published in Greenfield, Massachusetts, US * ''The Recorder'' (Port Pirie), a news ...

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 ( , ) , from , with the same meanings. is a period in European history The history of Europe is traditionally divided into four time periods: prehistoric Europe (prior to about 800 BC), classical antiquity (800 BC to AD ...

medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...

and also modern recorders have a cylindrical bore. Some tin flageolets also have a reverse taper.

Brasses

Brass instruments also are sometimes categorized as conical or cylindrical, though most in fact have cylindrical sections between a conical section (the mouthpiece taper or

leadpipe In a brass instrument, a leadpipe or mouthpipe is the pipe or tube into which the mouthpiece is placed. For example, on the illustration of a trombone, the leadpipe would be between #3 and #4, the mouthpiece and the slide lock ring. In the ...

) 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