waltz, romantic dance in moderate triple time. It evolved from the German Ländler and became popular in the 18th cent. The dance is smooth, graceful, and vital in performance. The waltz in Vicente Martin's opera Una cosa rara, produced in Vienna (1776), is regarded as the first Viennese waltz. This type was later made famous by the two Johann Strausses, father and son. The younger Strauss composed the Blue Danube Waltz, the most popular of the Viennese style. The waltz was introduced in the United States via England in the early 19th cent. Mozart, Chopin, Berlioz, Brahms, Richard Strauss, and Ravel have also composed waltzes.