The Sonata in B Minor “is music of drastic intellectuality, clothed in a Dantesque drama. Looking within the sonata’s mighty inner conflicts, one finds the most daring structural innovation in large-form composition since Beethoven. Claudio Arrau called it Beethoven’s 33rd sonata, probably meaning that had Beethoven lived, he would have eventually fused all elements of sonata form into a one-movement plan.”