The violone is most often used today as the contrabass bowed string instrument in early music groups performing Renaissance and early Baroque music. Only a few players specialize in the instrument, with most using contemporary reproductions rather than actual historical instruments.
After the decline of the other members of the viol family, the violone continued to have a place in orchestral music and, for example, Bach scored his cantatas for violone as the contra-bass instrument. It was eventually ousted by the modern double bass.
It is important to understand the etymology of the term "violone." "Violone" is a conjugation of the word "viola," not of the English word "viol," which is contemporarily used to refer to a member of the viola da gamba family. When use of the word "violone" began in the early sixteenth century, "viola" simply meant a bowed, stringed instrument, and did not specify viol or violin. Historically "violone" has referred to any number of larger fiddles, regardless of family. Sixteenth century instruments that at some time were (not incorrectly) called "violone" include the vihuela d'arco, or early viol, and later the bass violin (direct ancestor of the cello).
The term violone is sometimes used to refer to the modern double bass, which belongs almost as much to the viol family as to that of the violin, having sloped shoulders, a flat back (often) and tuning in fourths. The double bass, unlike the original violone, is an unfretted instrument.
"Violone" is also the name given to a non-imitative string-tone pipe organ stop, constructed of either metal or wood, and found in the pedal division at 16' pitch (one octave below written pitch), or, more rarely, 32' (2 octaves below written pitch).