Alwin Nikolais, a pioneering choreographer and composer who blended music and dance in a career that spanned more than 50 years, died Saturday of cancer. He was 82.Inspired by Mary Wigman, the leading German Expressionist dancer, he began studying dance in 1933 and choreographing in 1936. After World War II, he launched his own dance company and in 1948, he became associated with the Henry Street Settlement, where he launched the mixed-media dance spectacles that gained him international attention. His first multimedia production was “Masks, Props and Mobiles” in 1953. Nikolais’ other major works included “Kaleidoscope” in 1956, “Totem” in 1959, “Imago” in 1963, “Scenario” in 1971, “Gallery” in 1978, “Pond” in 1982 and “Crucible” in 1985. From 1979-81, Nikolais served as artistic director of the Centre Nationale de Danse Contemporaine in Angers, France.