Castil-Blaze is known first and foremost for his adaptations of German and Italian works. His adaptations, successfully performed over a long period of time, have been vehemently criticized for the liberties taken with the major works of Weber and Rossini. The present fashion and preference (perhaps illusory) for the original version overlook the coherence and real scope of Castil-Blaze’s intentions. As a theoretician and historian of lyric drama, this passionate scholar and fierce polemicist shows himself as a staunch defender of Italian music at the time of the great eighteenth-century disputes. He draws a highly negative portrait of French musical life, at least when compared to that of Germany and Italy. He sees such a deplorable state as a consequence of monarchic centralization and as a result of French disregard for opera. As a specialist of lyric-writing, he associates this medium with a musical and prosodic regularity that cannot be found in sound French aesthetics. Aware of his own limitations as a composer, he aims to « naturalise » Italian music so as to counterbalance the lack of authentic lyric drama. Taking as a starting-point his technical definition of lyricism, he follows a strict and methodological logic in his adaptations. His acknowledged aim is not to remain faithful to the original but to create a French version, using borrowed material able to reach larger audiences, particularly in the provinces. He thus means to democratize opera by attacking a harmful Parisian elitism. The undeniable success achieved by his works, in spite of the criticisms they met with, is a sure sign of victory. In this respect, Castil-Blaze can be seen as a leading figure in the diffusion of the Italian repertory throughout the nineteenth century.