Rameau's rejoinder to Rousseau's attack on French music in Lettre sur la musique fran‡aise (1753).

Rameau was a neo-classicist. He argued that a composer must use sound to evince harmony - eternal mathematical proportations emboided in the nature of things - not given to the mortal ear, but which give the pattern of musical sounds the order and beauty which the inspired artist creates or imitates.

The Erreurs include a violent attack on six articles on music Rousseau wrote for the Encyclopédie, (he wrote nearly 400, plus one on political economy). Rousseau wrote a rejoinder, the Examen de deux principes?.