Duke's avant-garde streak takes over at the edges of his catalogue. His pre-funk records are littered with abstract pieces like “Echidna's Surf”, a fusion piece composed by Frank Zappa and suffused with cosmic textures and synthy bass, and “Nigerian Numberuma”, a spaced-out pointillist number that utilises the percussiveness of African rhythms. Another experimental cut is the swirling “Phase 7”, from his orchestral jazz work, Muir Woods Suite.