Coiled brass wind instr. (tube over 11′ in all) of conical ¼′′ bore, with funnel‐shaped mouth‐piece and bell of 11–14′′ diameter. The hn. was one of the earliest primitive instrs., being used for military purposes and esp. for hunting. The modern hn. was developed in Fr. (hence the name). It has existed in 2 forms: (a) natural, but withcrooks. This is the instr. for which the older classical composers wrote and is said to have been introduced into the orch. by Lully in his comedy‐ballet La Princesse d'Elide, Paris 1664. A notational convention existed whereby if notes occurred low enough to demand the use of the bass clef, they were written an octave lower than that pitch demanded. All parts were written as if in the key of C, with sharps and flats inserted as accidentals. Certain notes not in tune with the modern tempered scale were modified by the insertion of a hand in the bell (‘stopped notes’). (b) with valves. The Fr. hn. was equipped with rotary valves in about 1827 and this instr. gradually displaced (a). Schumann was among the first to specify its use, and Wagner abandoned (a) in and after Lohengrin (1848). Traditionally the valved hn. is pitched in F, but other pitches exist. Compass is from B′ upwards for about 3 1 2 octaves. The ‘double hn.’ pitched in both F and B♭ alto, is normally used today. The valves act much as the old crooks did but of course more speedily. Notation is without key signature, written a perfect 5th higher than it is intended to sound. There is a modern tendency to use a key signature, which, from the use of the F pitch, necessarily has a flat less or sharp more than the actual key. The hn.'s place in the sym. orch. has grown in importance since the 19th cent., composers such as Mahler and Strauss sometimes specifying 8 hns. Orch. parts assume that the higher notes will be played by the odd‐numbered players, the lower by the even. Many hn. concs. have been written (e.g. by Mozart, Strauss, Hindemith), and it is also employed in chamber works (notably Brahms's hn. trio). The Fr. hn. is also used in military bands, but not in brass bands where the term is colloquially used to denote the ten. saxhorn.