"J.J. was born for music," Jean-Jacques Rousseau wrote of himself, "not to be consumed in its execution, but to speed its progress and make discoveries about it. His ideas on the art and about the art are fertile, inexhaustible." Rousseau was a practicing musician and theorist for years before publication of his first Discourse, but until now scholars have neglected these ideas. This graceful translation remedies both those failings by bringing together the Essay, which John T. Scott says"most clearly displays the juncture between Rousseau's musical theory and his major philosophical works," with a comprehensive selection of the musical writings. Many of the latter are responses to authors like Rameau, Grimm, and Raynal, and a unique feature of this edition is the inclusion of writings by these authors to help establish the historical and ideological contexts of Rousseau's writings and the intellectual exchanges of which they are a part. With an introduction that provides historical background, traces the development of Rousseau's musical theory, and shows that these writings are not an isolated part of his oeuvre but instead are animated by the same"system," this volume fashions a much-needed portal through which literary scholars, musicologists, historians, and political theorists can enter into an important but hitherto overlooked chamber of Rousseau's vast intellectual palace.