Rousseau’s Pygmalion can be seen as the theoretical culmination and the practical result of his lifelong thinking around and experimentation with theatre and music. But why did Rousseau choose the Pygmalion myth to tie all these ideas together? This chapter examines in what ways Rousseau’s Pygmalion can be seen as a direct response to his arch-enemy Jean-Philippe Rameau’s opera-ballet Pigmalion, written in 1748. It discusses why Rousseau would chose to reply so directly to Rameau’s Pigmalion, and how Rousseau’s Pygmalion communicates with Rameau’s opera-ballet, drawing on the two thinkers’ theoretical discussions.