Alto member of the violin family, having four strings tuned c g d1 a1 (c = C below middle C; a1 = A above middle C). About 2 to 7 cm (1 to 3.5 in) longer than the violin, and tuned a fifth lower, the viola varies more in size than do the violin and cello.
Most violas are resonant and mellow in the lower range and have rich, full sounds in the middle and upper ranges. The earliest surviving examples are two fairly large violas by the Italian builder Gasparo da Salo (1540-1609).
Used prominently in such early works as the opera Orfeo (1607) by the Italian composer Claudio Monteverdi, the viola in the late 17th and 18th centuries took a secondary role, and smaller models prevailed. With the viola's resurgence in compositions such as the symphonic poem Harold in Italy (1834) by the French composer Hector Berlioz, and works by the German composers Johannes Brahms and Robert Schumann, large violas again predominated.
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