Co-founder of the Cooperative Studio for Electronic Music and the now historic ONCE Festivals of Contemporary Music (from 1966 to 1974), Mumma was, with John Cage and David Tudor, one of the three composer-musicians associated with the Merce Cunningham Dance Company and for which he composed four commissioned works. With Robert Ashley, David Behrman and Alvin Lucier, he was part of the Sonic Arts Union - a pioneering live-electronic music ensemble. Mumma has made concert tours and recordings in North and South America, Europe, and Japan.