Louis Couperin
Influential composers included Jean-Baptiste Lully, Élisabeth Jacquet de La Guerre, Louis Couperin, François Couperin and Jacques Champion de Chambonnières. Jean Philippe Rameau, a prominent opera composer, wrote an influential treatise on musical theory, especially in the subject of harmony; he also introduced the clarinet into his orchestras. In the late Renaissance and early Baroque period, a type of popular secular vocal music called "Air de cour" spread throughout France.