OF COURSE, ANY BEETHOVEN MUSIC lover needs no prompting for listening to the Moonlight sonata or the Pathetique or the Waldstein or the Appassionata. I could make a case that many Beethoven sonatas are neglected even by musicians as Beethoven's private thoughts, not for consumption. This would make a reasonable case for prompting the listener to reconsider these somewhat neglected treasures. However, this is not why I wrote this book. To understand...