The bass saxophone is one of the largest members of the saxophone family—larger than the more commonly encountered baritone saxophone. It was the first type of saxophone presented to the public, when Adolphe Sax presented a bass saxophone in C at an exhibition in Brussels in 1841. The modern bass saxophone is a transposing instrument pitched in B♭, an octave below the tenor saxophone. The bass saxophone is not commonly used in any music, but it is heard on some 1920s jazz recordings; in free jazz; and in the saxophone choir or "large ensemble" tradition.
The instrument was first used in 1844, both by Hector Berlioz in an arrangement of his Chant sacred, and by Georges Kastner in his opera Le Dernier Roi de Judas. In the 1950s and '60s it enjoyed a brief vogue in orchestrations for musical theater: Leonard Bernstein’s original score for West Side Story includes bass saxophone, as does Meredith Willson’s Music Man and Sandy Wilson’s The Boy Friend. American composer Warren Benson has championed the use of the instrument in his music for concert band.