The contrabass clarinet and contra-alto clarinet are the two largest members of the clarinet family that are in common usage. Modern contrabass clarinets are pitched in BB♭, sounding two octaves lower than the common B♭ soprano clarinet and one octave lower than the B♭ bass clarinet. Some contrabass clarinet models have a range extending down to low (written) E♭, while others can play down to low D or further to low C. Some early instruments were pitched in C; Arnold Schoenberg's Fünf Orchesterstücke specifies a contrabass clarinet in A, but there is no evidence of such an instrument ever having existed.
The contrabass clarinet is also sometimes known by the name pedal clarinet, this term referring not to any aspect of the instrument's mechanism but to an analogy between its very low tones and the pedal tones of the trombone, or the pedal division of the organ.
Subcontrabass clarinets, lower in pitch than the contrabass, have been built on only an experimental basis.
The EE♭ contra-alto clarinet is sometimes referred to as the "EE♭ contrabass clarinet".
Read more about Contrabass Clarinet: Manufacturers, Performers, Compositions