“What what the paper archives make clear, through [Arthur] Russell’s personal notes — often written in small music-composition notebooks — is how much he sought to incorporate a conscious sense of openness and flexibility into his work. Some of his most useful notes, probably from the early 1980s, deal with ‘World of Echo.’ Here he wrestled with the idea of form and completeness in fascinating ways, often using the notation ‘p Idea’ (the p may have stood for parenthetical).”