In terms of its basic design, the TROMBONE is the simplest of the modern brass instruments, consisting of a mostly cylindrical brass tube with only two 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 changed by altering the fundamental length of the main tube using a large slide. There are seven slide positions (each one of which corresponds to one of the seven valve combinations possible on a three-valved instrument). In the first position, the slide is fully retracted and in the seventh the slide is fully extended. Each succeeding position lengthens the tube and lowers the fundamental pitch of the instrument by a half-step.
Many trombones, especially bass trombones, are fitted with valves which are located between the slide and the second bend. These are almost always rotary valves, operated by the player’s left thumb (assuming a right-handed player). Usually, only one valve is used, although trombones with two or three “triggers” are also used. The first valve is usually equivalent to the sixth position. A trombone with triggers should not be confused with the valve trombone, which is shaped like a trombone but with trumpet-style piston valves and no main slide. Valve trombones are generally inferior in sound and are rarely used in better ensembles.
Role in the Brass Band
In four-part arrangements, the trombones usually are assigned the tenor part (or the bass part for the bass trombone). In larger arrangements, the trombones are frequently used to “color” the sound, being used almost as an ornamental part of the band. The trombone is frequently featured as a solo instrument. In some compositions, the sound of the trombone is altered by the use of a straight mute or a cup mute.
Because of the bright quality of its sound, the trombone is used in combination with the cornets for a brilliant sound, or in contrast to the mellow instruments. When playing with horns and baritones, the sound of the trombone will easily dominate.
The Bass Trombone
The BASS TROMBONE is a larger version of the common tenor trombone. Most modern bass trombones have one or more valves (sometimes called “triggers”). Older bass trombones simply had extra-long slides, with a small swivel handle attached to allow the player to reach the lower positions. Bass trombones are sometimes termed E-flat, F or G trombones. In the brass band, the bass trombone part is unique because it is written at true pitch in the bass clef.
The bass trombone is the most powerful individual instrument in the brass band. The characteristic blare of a bass trombone fortissimo is a familiar and essential part of the brass band sound.