or viola da gamba
Bowed stringed instrument of the 16th–18th centuries.
The viols are distinguished from the violin family particularly by a fretted fingerboard, sloping shoulders, flat back, six strings, and milder tone. They exist in four sizes: treble, tenor, bass, and double bass (violone). They are played vertically, the body of the instrument being held between the legs or rested on the knee. The viol family appeared in the late 15th century and soon became widely popular and acquired a large repertory. Throughout the Baroque era, the bass viol joined the harpsichord in the basso continuo . The contemporaneous violin family, having a more penetrating tone, gradually displaced the viols in the 18th century.