cornet or cornet à pistons (Fr.). An instr. of brass (or other metal), of partly cylindrical and partly conical bore, with a cup-shaped mouthpiece. Like both tpt. and hn. it operates on the harmonic series filling in the gaps by the use of 3 valves which, singly or in combination, lengthen the tube so giving new fundamentals of a semitone to 6 lower, and consequently as many new harmonic series. Its tone is of a quality between that of the hn. and that of the tpt. Owing to the width of its bore it has great flexibility. Double and triple tonguing are possible. Like the tpt. as found in most Brit. orchs. it is constructed so that its primary key can be either B♭ or A, as desired: this removes some of the difficulties of playing in the extreme flat and sharp keys, as in the one case the player is eased of 2 flats and in the other 3 sharps. There is also a cornet in E♭, almost exclusively for wind-band use. In all these 3 keys the cornet is a transposing instr., its mus. being written respectively a tone or minor 3rd higher, or a minor 3rd lower.

The cornet's first orch. appearance seems to have been in Rossini's opera William Tell, in 1829, and cornets are used by Berlioz in several works, incl. the Symphonie Fantastique, by Bizet, and by Tchaikovsky in Francesca da Rimini. By the 1890s it had almost displaced the tpt. in the orch., but is now seldom found in the orch. or in dance bands, and is now chiefly used in brass and military bands where a sop. cornet in E♭ is also used. But some 20th-cent. composers specify its use where they want its particular tone-quality, e.g. Vaughan Williams in London Symphony, Lambert in Rio Grande, and Arnold in Beckus the Dandipratt.

cor·net / kôrˈnet/ • n. 1. Mus. a brass instrument resembling a trumpet but shorter and wider, played chiefly in bands. ∎  a compound organ stop with a powerful treble sound.2. Brit. a cone-shaped wafer, esp. one filled with ice cream.DERIVATIVES: cor·net·ist / -ˈnetəst/ (also cor·net·tist) n.

cornet Brass musical instrument similar to a trumpet. It was one of the first brass instruments to have valves and, therefore, capable of playing a full range of notes. Hector Berlioz was one composer to take advantage of this ability. Its range is about the same as a trumpet's, but its tone is mellower.

cornet wind-instrument XIV; conical twisted paper, and other transf. uses XVI. — (O)F., dim. of Rom. *corno, L. cornū HORN; see -ET.