The clarinet is a single-reed woodwind instrument. It is usually made of African Blackwood, ebony or plastic and has a cylindrical bore of about 0.6 inches. The lower end flares out into a bell. The mouthpiece, usually made of ebonite, has a slot like opening in one side over which a single reed, made from natural cane, is secured by a screw clip, or ligature. The player grips the mouthpiece, reed down, between his lips or lower lip and upper teeth.

The most common clarinet is the B flat soprano which has a range of about three and a half octaves from D to below middle C. It is about 26 inches long with about 20 or more side holes and key mechanisms. The cylindrical pipe, coupled to a reed mouthpiece, acts acoustically as a stopped pipe which also accounts for its deep-pitched fundamental register and characteristic tone colour

The predecessor of the clarinet was a folk instrument called the chalumeau or a small mode trumpet. The clarinet was developed in 1690 by Johann Christoph Denner, a well-known flute maker in Nurnberg. He made them out of boxwood, gave the chalumeau an attached reed and doubled its length.

The birth of the modern clarinet was between 1800 and 1850 where more keys were added to improve certain notes. Bores and mouthpieces were enlarged following general trends towards greater tone power. Technological advances, including keywork mounted on pillars, the ring keys introduced by the flute maker Theobald Boehm, and Auguste Buffet's needle springs, led in the 1840s to the appearance of the two principal modern systems.

The Albert system is named after its maker, Eugene Albert, of Brussels, Belgium. It has a complex auxiliary keywork but with conservative features in bore, mouthpiece and reed which gives it a deeper tone. This is the preferred system in German-speaking countries. The Boehm system, which is the norm in the orchestra in most countries, was patented by Hyacinthe E. Klose and Buffet. It incorporates much of Boehm's flute fingering system. It is distinguished from the other system by the ring at the back for the thumb and by four or five keys for the right little finger.

Orchestras in England, Scotland, France and Germany gradually took up the clarinet in the mid 1700. Mozart included clarinets in his Paris Symphony in 1778. He also wrote concertos, quintets, divertimenti and many other chamber works for the clarinet. His enthusiasm for the clarinet did a lot to establish it as an orchestral instrument, as most other composers of his time had been using it much less. The clarinet enjoyed something of a boom in the early nineteenth century and the repertoire began to expand. Louis Spohr wrote four concertos, Carl Maria von Weber contributed two concertos, a concertino and a duo for clarinet and piano.

Since then there have been many works from most major composers: Strauss, Saint-Saens, Debussy, Poulenc and Bartok amongst others. In the twentieth century the clarinet, with its great range and expressive capabilities, became a standard member of the jazz and swing band line-up. Stravinsky's jazz-inspired "Ebony Concerto" was written for clarinet and swing band. Other composers who have done the same include Hinderminth, Copland, Milhaud and Britten.

Jack Brymer is a senior figure in clarinet playing. He has an incredible list of recordings, both as a soloist and orchestral player. He and his eminent contemporary, Gervase de Payer, who went to the US and has also made many recordings, are probably the people who have influenced most clarinetists. Other top clarinetists include Tony Pay (he was first clarinetist with the London Sinfonietta and Nash Ensemble) and Alan Hacker. Hacker pioneered the early clarinet and was Professor of Clarinet at the Royal Academy of Music. He's one of the best players around and his control of the high notes is an example to all.