This chapter re-examines the controversy over the nature and extent of Rousseau's influence on the French Revolution of 1789. It does so against the background of the Lettre sur la musique françoise and the uprising which he claimed this work had averted, rather than in the more customary context of the Contrat social and the chain of political events that text may have heralded or initiated. It argues that in effect, if not by design, the Lettre constitutes a critique of the musical philosophy of Rameau—a critique which Rameau himself attempted to refute in his own replies to Rousseau's text. Moreover, it was in the course of Rousseau's formulations of his rejoinders to the counterattacks of Rameau that he came to develop the ideas of the Lettre as a part of his more general social theory—and, indeed, as that part which was to prove the most politically radical in tone and the most revolutionary in its implications.