clarinet

The sounding compass of the A clarinet (top); of the B flat (centre); and of the E flat (bottom).

Any of a family of single-reed woodwind instruments of cylindrical bore. It is one of the four main orchestral woodwinds, but did not join the orchestra until after the middle of the 18th century. In their concertos for clarinet, Wolfgang Amadeus Mozart and Carl Maria von Weber made good use of the instrument's wide range of tone from the rich, dark notes of the low register rising to brilliance in the high register, and its capacity for sustained dynamic control. The ability of the clarinet both to blend and to contrast with other instruments makes it popular for chamber music and as a solo instrument. It is also used in military and concert bands and widely as a jazz instrument.

The clarinet was developed from the double-reed chalumeau by the German instrument maker Johann Denner about 1700 and was occasionally used in the Baroque orchestra as an instrument of trumpetlike tone. In the 19th century, Theobald Boehm added a system of metal keys and levers to produce today's chromatic instrument. Hector Berlioz showed that the improved instrument had a raucous and shrill side to its character in the final ‘Witches' Sabbath’ movement of the Symphonie fantastique/Fantastic Symphony (1830). A broad range of clarinets are still in use, including soprano B flat and A (standard orchestral clarinets), alto F (military band), B flat bass, piccolo E flat and D, and curved contrabasses in E flat and B flat, the latter sounding two octaves lower than the soprano B flat, and virtually inaudible on its own.