A creator of modern music as a teenager, he later juggled a breezy pop sensibility with conceptual rigor. He was an important collaborator with the composer Robert Ashley.A creator of modern music as a teenager, he later juggled a breezy pop sensibility with conceptual rigor. He was an important collaborator with the composer Robert Ashley.Read MoreClassical Music, Deaths (Obituaries), Pop and Rock Music, Jazz, Tyranny, Gene ‘Blue’