A contrabass is a large European stringed instrument that belongs to the viol family. It produces deep (and very low) notes with a rich sound. It's lowest note is the E string (although this can be lowered even further with the help of a C extension or an additional string) which is the equivilant of the E two octaves below middle C on piano. The contrbass is common (although not nearly as common as a cello or violin) in jazz or classical pieces, although does not go very far in many other genres. Generally, the contrabass plays the harmony and is rarely given solos.