Les Masques, ou Changement de dames is a short ballet of 1933 choreographed by Frederick Ashton to music by Francis Poulenc. Ashton's biographer describes it as a miniature masterpiece, an inspired fusion of scenery, steps and music. David Vaughan comments that Ashton had wanted Poulenc to compose the score for his first ballet, A Tragedy of Fashion, and seven years on "was fully in command of the resources that could enable him to realise such a work" – witty, sophisticated and of its time. Later projects to collaborate between Ashton and Poulenc did not come to fruition.