The bass clarinet is a member of the woodwind instrument family. It is larger than a soprano clarinet (the most common type of clarinet) and produces lower notes, but the bass clarinet is played just like a clarinet, with many keys operated by the player's left and right hands.

Larger and differently shaped than the standard clarinets, the bass clarinet has a darker timbre that composers often exploit for expressions of gloom and doom, as Mahler does in his Sixth Symphony.

Bass clarinets are not hard to play, especially if you've already played the B-flat, or soprano, clarinet.

Common variants extend to either low C or low E♭. “A” bass clarinet — Very rare today, more common around 1900, though bass clarinets in A and C as well as B♭ were being advertised at least through 1927.

It plays and reads just like the B-flat clarinet, though it sounds an octave lower. This is a good thing because if you have played clarinet, you can pick up a bass clarinet and jump right in to playing it without needing to learn a new clef.

Bass clarinets are not hard to play, especially if you've already played the B-flat, or soprano, clarinet. This instrument is easier than the flute and bassoon and slightly harder than the saxophone. Most of the fingerings are the same, though the bass has extra keys that can be confusing at first.