The bass clarinet is made of wood, except for the valve mechanism which is made of metal. Its sound is produced by a mouthpiece and the reed attached under it.

Music for the bass clarinet can be written either in treble or bass clef. The French way of writing (the treble clef) is the most common, the German school utilizes the bass clef. The instrument sounds one octave lower than written.

The bass clarinet is used very much in the same way as the bassoon, and these instruments often share a score.

The bass clarinet is a transposing instrument - its material needs to be transposed one octave + major second up.

Recommended combinations:

Bass clarinet with the French horn(s)
Bass clarinet with the trumpet (a rare but well-functioning combination)
Bass clarinet with string pizzicato

Listen to the audio sample: