Beethoven’s final three piano sonatas have always been a source of great fascination. Composed in 1820, the Sonata op. 109 opened the door to the future with its extreme expressivity, its abandonment of traditional techniques and its radical departure from familiar aesthetic norms.

Beethoven specialist Jonathan Del Mar has competently solved the questions raised by the highly complex source material of this work headed “Sonata for the Hammerklavier” in the autograph score. The result is a rel...