distinguished French choreographer whose revolutionary treatise, Lettres sur la danse et sur les ballets (1760), still valid, brought about major reforms in ballet production, stressing the importance of dramatic motivation, which he called ballet d'action, and decrying overemphasis on technical virtuosity. His first choreographic success, Les Fêtes chinoises (1754), attracted the attention of David Garrick, who presented it in London in 1755. After producing such masterpieces as Medée et Jason and Psyché et l'Amour (at Stuttgart, 1760–67), he was appointed ballet master at the Paris Opéra in 1776.