Contrabass (from Italian: contrabbasso) refers to several musical instruments of very low pitch—generally one octave below bass register instruments. While the term most commonly refers to the double bass (which is the bass instrument in the orchestral string family, tuned lower than the cello), many other instruments in the contrabass register exist.
The term "contrabass" is relative, usually denoting a very low-pitched instrument of its type, rather than one in a particular range. For example, the contrabass flute's lowest note is approximately an octave higher than that of the contrabass clarinet. Instruments tuned below contrabass instruments, such as the double contrabass flute or subcontrabass saxophone, may be referred to as "double contrabass," "triple contrabass," "subcontrabass," or "octocontrabass" instruments. On the other hand, the "contrabass" classification often includes such instruments.