But there are exceptional cases, and the case of the 32 Beethoven piano sonatas is certainly one of them. The sonatas make up a wonderfully diverse yet utterly cogent and self-contained body of work.

So wrote Beethoven from the Austrian spa town of ... he spent the rest of the summer working on two piano sonatas, Op. 54 and Op. 57. He went for long walks in the nearby Vienna Woods, one of ...