Jean-Jacques Rousseau is one of the greatest philosopher-musicians in the history of music. Besides being one of the leading philosophers, he was also a composer and theorist of music. Whilst Jean-Philippe Rameau, his great musical contemporary and antagonist, was a great composer who wished to be accepted by the philosophers as one of their own, Rousseau was a great philosopher who always aspired to succeed as a musician. In 1748, Diderot entrusted Rousseau with many of the most important articles on music for the great Encyclopédie des Arts et Métiers, in which he criticized Rameau's theoretical and musical systems. Rousseau lived part of his life as a professional copyist, producing large-scale manuscripts, but also composed a substantial body of works of his own, most notably his opera, Le Devin du village (1752).