How do we decide what to value as music, or as poetry, or as art? For at least a century, since we were first told that noise might be music, and since Elsa von Freytag-Loringhoven, Kurt Schwitters, and Marcel Duchamp began to stick found objects in art galleries, critics have been increasingly suspicious of this question. The essays in this volume show, however, that an indirect but unexpectedly powerful answer is given by the very writers, composers...