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 only an experimental basis.

The EE♭ contra-alto clarinet is sometimes referred to as the "EE♭ contrabass clarinet".

Philip Glass (born January 31, 1937) is an American composer. One of the highest profile composers writing "classical" music today, he is often said to be one of the most influential composers of the late 20th century. His music is also often controversially described as minimalist, along with the work of the other "major minimalists" La Monte Young, Terry Riley and Steve Reich.

He has lately distanced himself from the "minimalist" label, describing himself instead as a composer of "music with repetitive structures." Though his early mature music shares much with what is normally called "minimalist", he has since evolved stylistically. Currently, he describes himself as a "Classicist", pointing out that he is trained in harmony and counterpoint and studied such composers as Franz Schubert, Johann Sebastian Bach and Wolfgang Amadeus Mozart with Nadia Boulanger.

Glass is a prolific composer: he has written works for the musical group which he founded, the Philip Glass Ensemble (with which he still performs on keyboards), as well as operas, musical theatre works, ten symphonies, eleven concertos, solo works, chamber music including string quartets and instrumental sonatas, and film scores. Three of his film scores have been nominated for Academy Awards.