Opened on March 30, 1977. Closed April 20, 1980 after 1,326 performances — 3.1 years. Broadway's longest-running special Mummenschanz is a Swiss mask theater troupe who perform in a surreal mask- and prop-oriented style. Founded in 1972 by Bernie Schürch, Andres Bossard, and Italian-American Floriana Frassetto, the group became popular for its play with bizarre masks and forms, light and shadow, and their subtle choreography. The name Mummenschanz is German for "mummery", or a play involving mummers. Mummer is an Early Modern English term for a mime artist. Wiki link