Clarinet, woodwind instrument, essentially a cylindrical-bore pipe sounded by a single beating reed that is clipped over a slot in a mouthpiece set in the upper end of the pipe. The lower end flares out into a bell. Modern clarinets are typically made of ebony (sometimes plastic) and have 20 or more side holes to produce different pitches; some are open, to be closed by the player's fingers, and others are covered by padded keys. The clarinet has a smooth and mellow tone, and is capable of great agility in playing fast scales and arpeggios. It can play loudly in all parts of its range, and exceptionally quietly in its lower range.
The most common size of clarinet, the B-flat soprano, has a range of about three and a half octaves; the lowest note is the d (written e) below c' (middle C). Notes above the lowest, or chalumeau, part of the range are obtained by depressing a speaker key and over blowing (increasing the speed of air blown into the instrument), which causes the instrument's air column to vibrate at a higher frequency. Being a cylindrical pipe stopped at one end, the clarinet over blows to the interval of a 12th above the fundamental pitch (unlike flutes and oboes, which over blow to the octave). Other less common sizes of clarinet are the A soprano (a semitone below the B-flat); the E-flat soprano (a fourth higher); the bass (an octave below the B-flat soprano); and the contrabass (an octave below the bass). The basset horn is an alto clarinet pitched in F, a fourth below the B-flat. Music for all clarinets is written as if for a C clarinet; on a B-flat clarinet the written note C sounds as B-flat. Players can thus switch instruments without learning new fingerings. The term B-flat applied to the clarinet refers to the notation, and not to the acoustic fundamental note (the lowest note) of the instrument (as it does when applied to trombones or tubas, for instance).
The clarinet was invented around 1700 by the German flute-maker Johann Christoph Denner as a modification of a folk reed pipe, the chalumeau. By about 1840 two complex systems of key work had evolved: the Boehm system, used in most countries, and patented in 1844 by the French builder Auguste Buffet, who adapted the flute improvements of the German builder Theobald Boehm; and the narrower-bore, darker-sounding system developed around 1860 by the Belgian maker Eugène Albert.
were accepted members of the orchestra by about 1780. Early works featuring the instrument
include the overture for two clarinets and horn (c. 1742) by George Frideric Handel and
the clarinet concerto (1791) by Wolfgang Amadeus Mozart. In the orchestra it did not often
feature as a solo instrument until the mid-19th century, when Brahms and Tchaikovsky
brought it to the fore in their symphonies and concertos. In the 20th century composers
such as Bart?k and
Ravel have made frequent use of its wide-range and agility in solo passages, as well as
using it to support the melody-line of other treble instruments.