Instruments

These pages are a simplified explanation of the workings and parts of a brass instrument. The actual science behind an instrument is quite complex, and this is not intended to be an exhaustive treatment.

Producing Sound

The Basics

Waves of compression and expansion, in a medium such as air, are detected by the ear and perceived as sound. The amplitude, or “height”, of the wave determines the volume. Volume is a measure of the sound’s loudness. The frequency, or wavelength, determines the pitch (highness or lowness) of the sound. Frequency is a measure of how many waves are detected over time, usually expressed in cycles per second. For example, the standard tuning note used in most modern orchestras is A 440, a note with 440 cycles per second. The higher the frequency, the higher the tone.

A brass instrument’s sound is produced by a vibrating column of air contained within the tubing. The origin of the sound is the lips of the player. A “buzz” is produced inside the mouthpiece of the instrument when the player pushes air through their lips. This sound is amplified and modified by the tubing of the instrument. Although the player blows into the mouthpiece in order to produce the necessary lip vibrations, the movement of the air through the tubing contributes little to the overall sound. It is the vibration of the air, not its passage through the instrument, that produces the sound.

The size and shape of the tubing produces the finished sound. The overall length of the tube determines the fundamental pitch. For a given length of tubing, each note that can be played is either the fundamental note or a note in the overtone series of the fundamental note. Overtones are secondary waves that arise from the fundamental note at higher frequencies. By adjusting the tension of the lips inside the mouthpiece, the player can select a particular overtone as the sound produced. This is why it is possible to play different pitches with the same length of tube.

Changing the Length

The earliest brass instruments were metal reproductions of animal horns. They had tubes of a fixed length, with no mechanism to change the length while playing the instrument. Skilled players could produce different pitches through lip tension and breath control, but true chromatic playing was difficult and only possible in the extreme upper range of an overtone series. Instruments such as the post horn and simple bugle are examples of this type of instrument that are still used today.

The difficulty in playing fixed-length instruments led designers to devise ways of changing the tube length while the instrument was in use. Lengthening the tube makes the fundamental note lower in pitch. Two main designs are used to accomplish this: the slide and the valve. Most modern brass instruments use valves, which lengthen the instrument by adding extra loops of tubing. The trombone uses a large slide to adjust the length of the tube. In addition to the valves or main slide, there are also smaller slides that are used to tune the instrument by making small changes to the tube length. The minimum number of valves needed to produce a fully chromatic instrument is three, which allows seven different combinations. These correspond to the seven slide positions on the trombone.

 

These pages are a simplified explanation of the workings and parts of a brass instrument. The actual science behind an instrument is quite complex, and this is not intended to be an exhaustive treatment.

Mouthpiece

The mouthpiece is the part of the brass instrument that rests against the player’s lips. It is the beginning of the tube that produces the sound. There are three basic parts to a mouthpiece:

For many players, the mouthpiece is the most important part of the instrument, because it is the point of contact. Subtle differences in the shape of the rim or the design and depth of the cup can profoundly influence the quality of the sound.

Leadpipe

The leadpipe is the starting point of the main tube, where the mouthpiece is inserted. The opening of the leadpipe is often reinforced, because any deviation from a circular cross-section could cause air to leak between it and the shank of the mouthpiece.

Main Tube

The main tube is the body of the instrument, extending from the leadpipe to the bell. On an instrument with valves, the main tube is divided into two portions by the valve assembly. Some portions are cylindrical, especially on the trombone, with its long slide. The larger portion of the main tube is conical, widening into a wide flare at the bell. Instruments with a larger portion of cylindrical tube are brighter in tone.

Valve

Mechanics

In general mechanical terms, a valve is a device that opens or closes a pathway for the passage of a liquid or a gas. Musical instrument valves are compound devices, where a single movement opens one passage and closes another. This has the effect of changing the length of the vibrating column of air within the instrument, thereby changing the fundamental pitch. This is analogous to an organ pipe, where larger, longer pipes produce lower tones.

There are various designs of brass instrument valves, but all work on the same general principle. The valve consists of a casing, to which the tubes attach. Inside the casing is a cylinder with ports bored through it for air to pass through the valve. These ports line up with the tubes attached to the casing. The cylinder either slides (a piston valve) or rotates (a rotary valve). The motion causes the ports to align in a different manner, connecting or disconnecting the passage from the tubes. When the valve is activated, the ports line up with a loop of tubing, which increases the length of the tube.

The graphic above is a schematic representation of a typical piston valve. In the “up”, or resting position, the air column passes through one passage of the valve, and the loop is bypassed. When the player presses down the valve core, this passage is closed and other passages align with the ports in the casing, diverting the path through the loop. This lengthens the air column and lowers the fundamental note. The larger the loop, the more the pitch is lowered. When the player releases the valve, a spring (not shown) returns the valve to the up position. Rotary valves spin instead of moving in a linear fashion, but the concept of ports opening and closing to lengthen the air column is the same.

In order for a valve to work properly, it is machined to very close tolerances. The valve must be able to move freely inside the casing, but must not allow air to leak around the cylinder. The ports in the casing and the body of the valve must align precisely. Any change in the diameter of the air column can change the tuning and sound quality of the instrument.

Usage

The basic modern brass instrument has three valves which are tuned approximately a half-tone apart. With three valves, there are seven different combinations that produce different notes. Valves are numbered beginning with the one closest to the leadpipe (in terms of the air path). Combinations are named based on the numbers of the valves in the activated (“closed” or “down”) position. If all of the valves are in the inactivated resting position this is termed “open”. Trombones have seven slide positions which correspond to the valve combinations, with each position lowering the fundamental note by a half-step.

Valve Combination	Trombone Position	Effect
Open	First (slide fully in)	None
Second	Second	0.5 steps lower
First	Third	1.0 steps lower
First + Second (Third)	Fourth	1.5 steps lower
Second + Third	Fifth	2.0 steps lower
First + Third	Sixth	2.5 steps lower
First + Second + Third	Seventh	3.0 steps lower

Compensation

All brass instruments with valves are constructed out of tune. The physics and mathematics are simply too complex for an instrument to be perfectly in tune for all valve combinations and all registers at all times. Although different designs have varying tuning characteristics, there are some things that are nearly universal. For example, the valve combination first + third is almost always sharp. Instrument designers have come up with several schemes to compensate for these problems.

On some instruments, mechanisms are provided that allow the player to move one or more of the tuning slides while playing the instrument. For example, on many cornets, rings or levers are provided that allow the player to lengthen the slides on the first and third valve slides, in order to correct the sharpness of the first + third valve combination. Another approach is to add more valves. For example, almost all euphoniums used in brass bands have a fourth valve, which lowers the sound 2.5 steps, or the same amount as the first + third combination. The fourth valve also allows more chromatic notes at the extreme low range of the instrument. In recent years, manufacturers have produced instruments with both extra valves and slide levers, for maximum flexibility in keeping the instrument in tune throughout the octave. A third method is to add extra tubing which comes into use only when certain valve combinations are played.

Slides

Every brass instrument has one or more slides that are used to make small adjustments to the length of the air column in order to tune the instrument. These are commonly referred to as “tuning slides”. There is always one slide somewhere in the main tube for the overall pitch of the instrument, even on trombones. Usually, there is also a slide on each major valve loop. As mentioned in the Compensation section above, sometimes these slides are connected to systems which allow the player to move them while playing the instrument.

Bell

The bell is the flare at the end of the main tube opposite the mouthpiece. The amount of flare varies widely with different instrument designs. This part of the instrument as a small influence on the sound of the instrument.

Definition of a Brass Band

The strict definition of a British-style brass band requires that only brass and percussion instruments are used, no strings or reeds. Intruments include:

• Cornet
• Flügelhorn
• Tenor Horn (Alto Horn)
• Baritone Horn
• Trombone
• Euphonium
• Bass (Tuba)
• Percussion

In a contest band, the number of players on each instrument and part is fixed by rule. Salvation Army bands have no set size or instrumentation, although various series of publications have consistent parts. Music for Salvation Army bands is published for ensembles with as few as four players. A typical lineup for a “full-size” Salvation Army band would be similar to:

• 1 E♭ soprano cornet
• 8 – 10 B𝄬 cornets
• 1 B𝄬 flügelhorn
• 4 – 6 E𝄬 tenor horns
• 2 – 4 B𝄬 baritone horns
• 2 – 4 tenor trombones
• 1 bass trombone
• 2 euphoniums
• 2 E𝄬 basses
• 2 B𝄬 basses
• 2 – 4 percussionists

The most basic arrangements for a band consist of four parts, corresponding to the four basic voice parts in a choir—soprano, alto, tenor, bass. A normal distribution would look something like this:

Instruments	Voice Parts
Cornet, Flügelhorn	Soprano, Alto
Horn	Alto, Tenor
Baritone	Tenor
Trombone	Tenor, Bass
Euphonium	Tenor, Bass
Bass (Tuba)	Bass

Composers frequently combine the instruments in different ways to achieve the musical effect that they desire. Different combinations can make the sound remarkably different even if all of the notes are exactly the same.

Color

In a musical context, the term color refers to a quality of sound. This can be described in terms of light: “bright” sounds or “dark” sounds. A bright sound is clear and ringing. A dark sound is mellow and complex. In general, brass instruments are bright when compared with other orchestral instruments. One of the limitations of an all-brass instrumentation is that the range of color is relatively small.

Within the family of brass instruments, there are shades of color. An instrument with a mostly cylindrical bore, such as the trombone, are the brightest. Mellow instruments, such as the euphonium and flügelhorn, have a conical bore. In the typical brass band, the cornets and trombones are the bright instruments, the flügelhorn and euponium are the mellow instruments, and the others are somewhere in the middle, although tending more to the mellow end of the spectrum.

Composer employ several different methods of extending the color range of the brass band. Mutes of various type have the most pronounced effect. More subtle differences can be introduced by the use of different keys and pitch registers. Well-trained players have some control over the brightness of the sound.

The cornet is a close relative of the trumpet. The standard instrument in brass bands is the B𝄬 cornet. Its pitch range is the same as that of a trumpet. It is the most numerous instrument in the brass band, with about a third of the players using cornets. A full brass band also includes a soprano cornet, pitched in E𝄬, which is smaller than the B𝄬 cornet.

Physical Description

The cornet is the smallest instrument in the brass band. The main tube has a moderately conical bore, gradually widening from the leadpipe to the bell flare. Most cornets have three piston valves. The instrument is usually equipped with a ring or lever on the third valve slide, and often also on the first valve slide. These are used to compensate for tuning problems which are inherent to all brass instruments.

Brass arrangers and composers sometimes modify the sound quality of the cornet by specifying various kinds of mutes, which are inserted into the bell. The two most common are the straight mute and the cup mute. More subtle changes in timbre can be achieved by writing in a high or low register, varying the key, instructing the player to play with the bell close to the music stand, use of dynamics, and the presence or absence of vibrato.

Role in the Brass Band

In a brass band, the cornet supplies the principal soprano voice. This instrument occupies a position in the band similar to that of the violin in a symphony orchestra. In small groups, the cornet is almost always the principal melody instrument. However, even in small groups (such as a sextet), there are usually at least two cornet parts, with the second part supplying the alto voice.

In more complex arrangements, the cornet section is sometimes split into three or four parts. The parts are often subdivided as divisi into two, three, or more voices. Because the cornet is the highest-pitched instrument in the brass band, and because its tone is relatively bright, it is capable of “cutting through” and being heard even when the entire band is playing. The agility and speed which can be achieved by a skilled cornet player also make it a favored instrument for solo items, both with and without full band accompaniment.

Because of its small size and relatively low cost, the cornet is the instrument most often used for beginner instruction.

Cornet vs. Trumpet

Although the length of the main tube is the same on both cornets and trumpets of the same pitch, the arrangement of the tubing is different. The trumpet’s tube is straighter, with fewer curves and loops. This makes the instrument longer in terms of the distance between the player’s lips and the end of the bell. Not only does the cornet have a more complex tubing design, the tube itself is conical over a larger portion of the length. Both the complexity of the tubing and the slope of the bore influence the final sound of the instrument. The tone of the trumpet is clearer (closer to a pure sine wave). The cornet’s sound is generally more gentle and warm than that of the trumpet. Trumpeters rarely employ vibrato, but this technique is commonly used by cornetists.

Soprano Cornet

Larger bands usually include an E𝄬 soprano cornet. This instrument is pitched a perfect fourth higher than the B𝄬 cornet. Because it has the highest range in the band, it can be heard above the full band. This variant of the cornet is considered a difficult instrument to play, in part because of the exposed nature of its parts. There is almost always only one soprano cornet in a band. Soprano players are considered specialists. Although it has the same agility as the B𝄬 cornet, and is generally played by a skilled person, the soprano cornet is not often used as a solo instrument.

The word horn is often used as a generic term for any brass instrument. In brass band instrumentation the horn section consists of upright saxhorns pitched in E𝄬, called tenor horns or alto horns. The most common figuration is the straight upright, with the bell pointing upward. Marching versions with the bell facing front are sometimes seen. Almost all tenor horns are constructed with three valves. Many newer designs have triggers, or levers, which move the tuning slides to help compensate for the intonation issues inherent to all brass instruments.

Role in the Brass Band

The E𝄬 tenor horn is considered one of the “mellow” instruments in the brass band. In four-part arrangements, the horns are used for the alto and tenor voices. Because the range of the horn is between that of the bright-sounding cornets and trombones, the darker sound is sometimes difficult to hear. However, the horn sound is a key component of the overall sound of a brass band, anchoring the “middle” of the band. The horn is also used as a solo instrument, though not as frequently as the cornet or euphonium.

Tenor Horn vs. French Horn

The orchestral French horn is built in a circular pattern, and is played with the bell facing down and toward the rear. The modern French horn is usually a double horn, pitched in F and B𝄬, with three rotary valves and a fourth valve that switches between the F and B𝄬 halves of the horn. Unlike most brass instruments, the valves are operated with the left hand. The right hand is positioned in the flare of the bell and is used to partially control the sound and pitch of the instrument.

A French horn mouthpiece is smaller in diameter than that of the tenor horn and has a deep, funnel-shaped cup. The flare of the bell is very wide. The tubing of a French horn is considerably longer than that of the tenor horn (the fundamental note of a F horn is the same as that of an F tuba). Because of the small mouthpiece and narrow bore of the French horn, the player is always playing in the upper partials of the notes. This makes the sound very intense, but sometimes difficult to control. Special effects, such as the fast lip arpeggio, commonly referred to as a “rip”, are possible because the overtones are close together in the upper range.

The use of the tenor horn instead of the French horn is rooted in tradition. Many brass bands play on the march, and a French horn is difficult to play while marching. The tone quality of the tenor horn is also a better blend with the other instruments of the brass band, some of which are also from the saxhorn family.

The baritone horn is a member of the saxhorn family like the tenor horn. Baritones are built in a similar pattern to the tenor horn, with an upright pattern. It is pitched in B𝄬, a perfect fifth below the tenor horn and in the same octave as the tenor trombone and euphonium. The bore is moderately conical, and the color of the sound is midway between the bright sound of the cornet and the mellow sound of the euphonium. There are three or four valves, usually of the piston design, with the fourth valve lowering the pitch by 2.5 steps, the same as the combination first + third, which is always sharp. Some newer baritones include a lever (trigger) mechanism to moves a tuning slide so that the pitch can be altered while the instrument is in use.

Role in the Brass Band

The baritone is gneerally assigned the tenor part in a four-part arrangements. Full-band instrumentation generally has two baritone parts. The baritone is often used to supply a bass note to the horn section. and also frequently doubles the euphonium parts. The baritone is not often used as a solo instrument, having been traditionally considered as less agile and interesting than the euphonium. However, the advent of the four-valve baritone has extended its range downward. In recent years, especially in the contesting band arena, baritone solos and solo specialists have become more common.

The trombone is the simplest of the modern brass instruments, consisting of a mostly cylindrical brass tube with only two major bends. The bell flare generally begins near the second bend (which is also the most common location for the tuning slide), covering one-fourth to one-third of the length of the tube.

The tenor trombone is pitched in B-flat, with a nominal fundamental tube length of nine feet. The range is identical to that of the baritone horn. Because the bore of the instrument is straight and cylindrical for much of the length, the trombone has the brightest sound of any of the usual brass band instruments. The slide makes the instrument capable of unique effects, the most well-known being the glissando.

The pitch of the instrument is altered by changing the length of the main tube using a large, freely-moving slide. There are seven slide positions, each corresponding to one of the seven valve combinations on a three-valved instrument. In the first position, the slide is fully retracted.. Each succeeding position lowers the fundamental pitch by one half-step.

Role in the Brass Band

In four-part arrangements, trombones are assigned the tenor or bass part in the case of the bass trombone. In larger arrangements, trombones are often used to color the sound, The trombone is often used as a solo instrument. As with the cornet, the trombone sound is frequently altered by using various types of mutes, the most common being the straight mute and the cup mute.

Because of its bright timbre, the trombones often combine with the cornets for a brilliant sound, in or in contrast to the mellow instruments of the band. When combined with tenor horns and baritones, the trombone sound can easily dominate.

Bass Trombone

The bass trombone is a larger version of the common tenor trombone. Modern bass trombones have one or more valves, operated with the players left hand. These are sometimes referred to as “triggers” becaue of the operating mechanism. Older bass trombones without valves had extra-long main slides, with a small swivel handle attached to allow the player to reach the lower positions. Bass trombones are sometimes referred to as E𝄬, F, or G trombones. In the brass band score, the bass trombone is unique as the only instrument with parts written in the bass clef at concert pitch. All other brass instruments in the band use parts written in the treble clef, even the tubas.

There is generally only one bass trombone in a band, and players are considered specialists. It is rarely used as a solo instrument. The most powerful instrument in a brass band, the chacteristic blare of the bass trombone fortissimo is a familiar and essential part of the brass band sound.

This section of the Brass Crest gives a basic understanding of how brass instruments work, the instrumentation of a brass band, and individual pages with descriptions of each type of instrument used.

• Generic Brass: Sound
• Generic Brass: Parts of an Instrument
• Instrumentation
• Cornet
• Tenor Horn
• Baritone
• Trombone

The euphonium is a small version of the tuba, usually constructed in an upright pattern. Most modern euphoniums are constructed with four valves of the piston type, although three-valve models are also seen. The instrument has a large, strongly conical bore, making the sound of the instrument dark and rich. The range is similar to that of the baritone and the tenor trombone, although the lower registers are generally better in quality than on instruments with a smaller bore.

Role in the Brass Band

The euphonium is the principle tenor voice of the brass band. Its role is similar to that of the cello in a symphony orchestra. The sound is more powerful than that of the baritone, although it can be overwhelmed by the bright choir of trombones and cornets. A full-sized brass band has two euphoniums, and the part is frequently written in divisi. In Salvation Army music, the euphonium is often assigned the counter-melody in contrast to the melody in the cornets.

The euphonium is frequently used as a solo instrument, with solos being more common than for any of the other brass band instruments except for the cornet.

The bass or tuba is the lowest-pitched instrument used in the brass band. Two types are used, the E𝄬 bass and the B𝄬 bass (sometimes referred to as the “double B𝄬 bass”). Tubas are the largest brass instruments, and there are many different patterns and designs in use. The ones most often used in brass bands are in an upright pattern, similar to the euphonium, and have three or four valves of the piston type.

The tubas used in symphony orchestras are most often pitched in F or C. They are also usually upright in pattern, but many are constructed with rotary rather than piston valves. Since orchestral parts are generally written in bass clef, indicating the actual concert pitch to be played, the choice of which tuba to use is often left to the discretion of the player. In marching bands, the helicon or wrap-around tuba (in America, these tubas are commonly referred to as Sousaphones) is often used. These tubas wrap entirely around the player’s body, with a very large flared bell pointing forward. This type of tuba is generally inferior in sound to the upright versions, but is ideal for its intended marching application.

The bore of the typical bass is conical, and the instrument’s sound is on the mellow side. However, because of the depth of the sound, tubas are not regarded as having any particular bright or dark timbre. The tuba is used in almost any combination with the other instruments of the band. The size of the instrument makes it the least agile and responsive of the brass band instruments.

E𝄬 Bass

The E𝄬 bass is the smaller of the two types of tuba used in the brass band. A full-size brass band has at least two E𝄬 basses, and the part may be written as divisi, frequently in octaves. Although its large size and long main tuba make it less responsive than smaller instruments, it is occasionally used as a solo instrument.

B𝄬 Bass

Role in the Brass Band

As in any musical group, the role of the bass instruments in a brass band is to provide a foundation for the rest of the sound. An essential component of all good brass bands is a powerful bass section, which is sometimes felt rather than heard. In the hands of a skilled player, the bass can be an effective melodic instrument, although solo bass passages are rare.