"It is the spirit which holds together noble and better men on this earth that is now addressed to you", Beethoven wrote thus to the dedicatee of the Sonata op. 109, the nineteen-year-old Maximiliane Brentano in 1821. Beethoven had already composed a little piano trio (B flat major WoO 39) for her in 1812.

And now she was receiving a very different kind of work - the first of the heavyweight last three piano sonatas. It remains astounding that Beethoven initially wrote the first movement as ...