With warmth, modesty and infectious enthusiasm, Boulez explains the hidden architecture of his most recent work, Sur Incises, to a non-specialized young audience. On a number of occasions, Pierre Boulez has shown that he can come up with the right words and gestures to throw a light on complex musical scores. Here he demonstrates his teaching talents in talking about his work as a composer: after conducting the nine soloists of the Ensemble Intercontemporain, who follow him with visible pleasure through the mysteries of a spectacular score, he offers a witty exposition of the musical movements that make up its construction.