Trombone — Chambers's Encyclopaedia

Trombone, a brass musical wind-instrument, whose title, originally Italian, signifies the great tromba or Trumpet (q.v.), to which instrument it forms the natural complement. It consists of a tube bent twice on itself, ending in a trumpet-shaped bell, and sounded by means of a cupped mouthpiece. The centre section (a in fig.) is double, the outer tube sliding on an inner one so as to permit of its being stretched to nearly double its own length. The performer, while holding the mouthpiece with the left hand, moves the slide out and in with the right hand by means of the cross-piece, b. The bass form of the instrument is provided with a jointed handle to enable the performer to reach the end of the slide. The trombone is, like the violin, a perfect instrument, being capable by means of the slide of any gradation of tone. Its notes are not fixed like the valved instruments, but made by moving the slide to varying distances, and consequently requiring a very correct ear on the performer's part.

A technical diagram of a trombone, showing its long, curved tube and the sliding mechanism. The diagram is labeled with 'a' for the central double section and 'b' for the cross-piece that allows the slide to move in and out. — Tenor Trombone.

It has the usual open harmonic notes of the tube (see HARMONICS), the slide giving the complete chromatic scale. One great advantage it has over keyed or valved instruments—viz. all its notes are of the same quality; the moving of the slide does not alter its form as in the valved instruments, where every valve opens an extra convolution for the air to go through. It is of ancient but uncertain date, some authorities tracing it back to nearly 700 B.C. Specimens made of bronze, with gold mouthpieces, were discovered at Pompeii in 1738. When first introduced into England it was called sackbut. It has been much used in orchestral composition, and as a military-band instrument is unrivalled. To partly get over its difficulties a form with valves instead of the slide has been introduced, but its brilliancy is thereby destroyed, and its use is consequently declining. It has been made in almost every key, but the two principally used are the tenor in B♭ and the bass in G; and the music for them is written in the tenor and bass clefs respectively.