HORN, a musical instrument, varying in form and in quality of sound. Each horn has a cup-shaped mouth-piece, by blowing into which, with a particular management of the lips, the sounds are produced. The ancient coronets, of different sizes, straight-shaped, formed of wood, &c., need not be described here, as they are disused. The common hunting-horn is of copper or brass, and bent into a semi-circle. The French horn is made of brass, and consists of a tube bent into circular convolutions, and terminating in an expansion of the tube, called the bell or pavilion. There
are generally two French horns used in orchestras, or in military bands,—a first and a second horn,—and these are furnished with crooks which alter the length of the tube, so as to adapt the horns to the different keys of the music to be played. The natural or open sounds follow the harmonic progression 1, 2, 3, 4, 5, 6, 7, &c.; but by placing the hand, or a cone of pasteboard, within the bell, the intermediate tones and semitones may be produced, and a scale formed, more or less pure and accurate. (See Music, § Horn.) Finger-keys were at one time applied to some horns, but have been superseded by pistons. The old bugle-horn is now the pistoned cornet or cornepan. Of late years, C. J. Sax of Brussels has greatly improved all instruments of the horn kind, as well as flutes, clarinets, &c. The German bass-horns are made of wood, and have finger-holes and finger-keys. The bass-horn and the English horn are not really horns, the former being only a large clarinet, and the latter a large oboe, with some peculiarities of form. See Appendix to G. F. Graham's Essay on Musical Composition, Edin. 1838.