 These days the most popular clarinet is the B ♭ clarinet. However, the clarinet in A, just a semitone lower, is commonly used in orchestral music. Since the middle of the 19th century the bass clarinet (nowadays invariably in B ♭ but with extra keys to extend the register down a few notes) has become an essential addition to the orchestra. The clarinet family ranges from the (extremely rare) BBB ♭ octo-contrabass to the A ♭ piccolo clarinet. The clarinet has proved to be an exceptionally flexible instrument, equally at home in the classical repertoire as in concert bands, military bands, marching bands, klezmer, and jazz.
