Since the founding of the Boulez Ensemble, sur Incises—the extraordinary work for three pianos, three harps, and three percussionists written by the group’s spiritual patron between 1996 and 1998—has formed a central part of its repertoire. For the opening of the Pierre Boulez Saal’s fourth season, Daniel Barenboim and the ensemble pair this landmark score of the late 20th century with Béla Bartók’s 1937 Sonata for Two Pianos and Percussion—a piece that Pierre Boulez himself considered one of the highpoints in Bartók’s oeuvre and that helped shape his own musical development. Ludwig van Beethoven’s youthful Horn Sonata serves as the curtain raiser for this concert—and for the Beethoven Year at the Pierre Boulez Saal.