Morton Feldman met John Cage at a concert of Webern’s music in 1950, and the two became firm friends. Like Cage, Feldman experimented with non-standard notation and elements of chance in his early compositions, but he is best-known for his later “long pieces”, of which the 1979 String Quartet was his first. The work is typical of Feldman in its use of muted instruments, soft dynamics and slowly unfolding musical structures.