viol, family of bowed stringed instruments, the most important ensemble instruments from the 15th to the 17th cent. The viol's early history is indefinite, but it is recognizable in depictions from as early as the 11th cent. During the second half of the 17th cent. it lost its dominant position to the violin family and became practically extinct until the general revival of interest in early music and instruments in the 20th cent. The viol differs from the violin in the manner of playing, in its shape, and in having frets and typically six strings, tuned in fourths with one third, rather than in fifths. Most viols are properly played upright, resting on or between the knees, with the bow held with the palm upward. The viol usually has sloping shoulders, a flat back, and deeper ribs than the violin. It is a chamber instrument with a soft, sweet tone, incapable of the dynamic extremes and brilliance of the violin; this helps to account for its decline. The viol was built in four principal sizes—treble, alto, tenor, and bass—which were used in ensemble, or "consort." The double-bass viol, or violone, survived all the others, becoming, with some modification, the present double bass. The bass viol was the principal solo instrument of the family, possessing a large literature from the 16th to the 18th cent. It later became known as viola da gamba [Ital.,=leg viol]—originally the name of the whole family, to distinguish them from those of the viola da bracchio (arm viol) family, the forerunners of the violin. The viola d'amore, a member of the viol family, originated in the 17th cent. and was especially popular in the 18th cent. It has from five to seven strings, tuned in thirds and fourths, and an equal number of sympathetic strings running through the bridge and under the fingerboard. Unlike most viols, it is held, like the violin, under the chin. It was and is principally a solo instrument, possessing a modest literature from all periods, including the 20th cent.