Brass instrument valve in the context of "Bass trombone"

A brass instrument is a musical instrument that produces sound by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips. The term labrosone, from Latin elements meaning "lip" and "sound", is also used for the group, since instruments employing this "lip reed" method of sound production can be made from other materials like wood or animal horn, particularly early or traditional instruments such as the cornett, alphorn or shofar.

There are several factors involved in producing different pitches on a brass instrument. Slides, valves, crooks (though they are rarely used today), or keys are used to change vibratory length of tubing, thus changing the available harmonic series, while the player's embouchure, lip tension and air flow serve to select the specific harmonic produced from the available series.

The horn (the term French horn refers to horns with pistons, not with rotary valves) 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 often used by players in professional orchestras and bands, although the descant and triple horn have become increasingly popular. A musician who plays a horn is known as a horn player or hornist.

Pitch is controlled through the combination of the following factors: speed of air through the instrument (controlled by the player's lungs and thoracic diaphragm); diameter and tension of lip aperture (by the player's lip muscles—the embouchure) in the mouthpiece; plus, in a modern horn, the operation of valves by the left hand, which route the air into extra sections of tubing. Most horns have lever-operated rotary valves, but some, especially older horns, use piston valves (similar to a trumpet's) and the Vienna horn uses double-piston valves, or pumpenvalves. The backward-facing orientation of the bell relates to the perceived desirability to create a subdued sound in concert situations, in contrast to the more piercing quality of the trumpet. A horn without valves is known as a natural horn, changing pitch along the natural harmonics of the instrument (similar to a bugle). Pitch may also be controlled by the position of the hand in the bell, in effect reducing the bell's diameter. The pitch of any note can easily be raised or lowered by adjusting the hand position in the bell. The key of a natural horn can be changed by adding different crooks of different lengths.

The trombone is a musical instrument in the brass family. As with all brass instruments, sound is produced when the player's lips vibrate inside a mouthpiece, causing the air column inside the instrument to vibrate. Nearly all trombones use a telescoping slide mechanism to alter the pitch instead of the valves used by other brass instruments. The valve trombone is an exception, using three valves similar to those on a trumpet, and the superbone has valves and a slide.

The word trombone derives from Italian tromba (trumpet) and -one (a suffix meaning 'large'), so the name means 'large trumpet'. The trombone has a predominantly cylindrical bore like the trumpet, in contrast to the more conical brass instruments like the cornet, the flugelhorn, the baritone, and the euphonium. The two most frequently encountered variants are the tenor trombone and bass trombone; when the word trombone is mentioned alone; it is mostly taken to mean the tenor model. These are treated as non-transposing instruments, reading at concert pitch in bass clef, with higher notes sometimes being notated in tenor clef. They are pitched in B♭, an octave below the B♭ trumpet and an octave above the B♭ contrabass tuba. The once common E♭ alto trombone became less common as improvements in technique extended the upper range of the tenor, but it is regaining popularity for its lighter sonority. In British brass-band music the tenor trombone is treated as a B♭ transposing instrument, written in treble clef, and the alto trombone is written at concert pitch, usually in alto clef.

The euphonium (English: /juˈfoʊniːəm/ yoo-FOH-nee-əm; Italian: eufonio; Spanish: bombardino) is a tenor- and baritone-voiced valved brass instrument pitched in 9-foot (9′) B♭ an octave below the B♭ trumpet or cornet, employed chiefly in brass, military, and concert bands. 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 four valves, usually compensating piston valves, although instruments with four or five rotary valves are common in Eastern and Central Europe.

Euphonium repertoire can be notated in concert pitch in the bass clef, or in the treble clef as a transposing instrument in B♭. In British brass bands, it is typically treated as a treble-clef instrument, while in American band music, parts may be written in either treble clef or bass clef, or both. A musician who plays the euphonium is known as a euphoniumist, a euphonist, or simply a euphonium player.

The bugle is a simple signaling brass instrument with a wide conical bore. It normally has no valves or other pitch-altering devices, and is thus limited to its natural harmonic notes, and pitch is controlled entirely by varying the air and embouchure.

The baritone horn, or often simply the baritone, is a valved brass instrument pitched in B♭ in the saxhorn family, employed chiefly in brass, military and concert bands. It has three or sometimes four valves, usually piston valves, although rotary valves are common in Eastern and Central Europe, where it is called the Tenorhorn. The bore is moderately conical, like the E♭ tenor horn and cornet, although narrower than the closely related euphonium and other valved bugles, like the flugelhorn and tuba. It uses a wide-rimmed cup mouthpiece of similar dimensions to trombone and euphonium mouthpieces. Like the trombone and the euphonium, the baritone can be considered either a transposing instrument reading B♭ treble clef, or a non-transposing instrument in bass clef.

In British brass bands, the standard instrumentation includes parts for two baritones, in addition to two euphoniums. In US concert band music there is often a part marked baritone, but these parts are commonly intended for, and played on, the euphonium. A baritone can also play music written for a trombone due to similarities in timbre and range.

The valve trombone is a brass instrument in the trombone family that has a set of valves to vary the pitch instead of (or in addition to) a slide. Although it has been built in sizes from alto to contrabass, it is the tenor valve trombone pitched in B♭ an octave lower than the trumpet which has seen the most widespread use. The most common models have three piston valves. They are found in jazz and popular music, as well as marching bands in Europe, where they are often built with rotary valves and were widely used in orchestras in the 19th century.

The superbone (sometimes known as the double trombone) is a duplex (or "hybrid") tenor trombone in B♭ that has both a slide, like a regular trombone, and a set of valves like a valve trombone. It is a relatively rare instrument.

The ophicleide (/ˈɒfɪklaɪd/ OFF-ih-klyde) is a family of conical-bore keyed brass instruments invented in early 19th-century France to extend the keyed bugle into the lower range. Of these, the bass ophicleide in eight-foot (8′) C or 9′ B♭ took root over the course of the 19th century in military bands and as the bass of orchestral brass sections throughout Western Europe, replacing the serpent and its later upright derivatives. By the end of the 19th century, however, it had been largely superseded, in bands by the euphonium and in orchestras by early forms of the modern tuba, some developed from valved ophicleides. The late 20th century saw a revival of interest in the instrument for historically informed performance practice, and ophicleides are built by a small number of manufacturers.