I read Charles Rosen's The Classical Style in the late 1970s, not so long after it was first published. I loved it then and still recommend it to people all the time. It's gracefully written, erudite, witty, and penetrating; Rosen has not only an excellent analytical mind but a performer's long experience with many of the works he wrote about. And the book's broad synthesis was a marvelous anodyne to modern analytical tendencies, which have tended to eschew discussions of style in favor of discussions of the Urlinie.
Rosen's April 23 lecture at the Palace of the Legion of Honor was much of a piece with The Classical Style and his other books. He ranged over the whole of Beethoven's late work, from the piano sonatas to the symphonies to the quartets to the Diabelli Variations, discussing Bach, Mendelssohn, and Mozart in passing and playing all manner of musical examples from memory. There was some hyperbole, and much wit and insight.
He didn't say a word about the last three sonatas, but the program notes for the concert were taken from his own Short Companion to the sonatas. Overall, the concert itself struck me as excellent, with intermittent moments of greatness and quite a few really beautiful things. I loved especially his work in the left hand, which brought out the bass lines and inner voices without blurring or obscuring anything. But somehow the whole fell short of transcendence, and I guess that's what I'd like in late Beethoven, especially in op. 111. Op. 109 was generally weak, op. 110 much better, op. 111 mostly well-played but ultimately disappointing.
There are some specific problems I can point to. I thought Rosen almost never played softly enough; I couldn't tell if it was an especially loud piano in a very tiny theater, or if he was being extremely literal about the fairly narrow range of notated dynamics. This is a real problem in the second movement of op. 111, where the arietta needs to sing and needs to have lots of room for emotional and dynamic expansion. It wasn't quiet enough; just as bad, he took the theme at a tempo I was sure he could not sustain through the 2nd and 3rd variations. Indeed, he took var. 1 at the same speed as the arietta, then slowed down for the subsequent variations.
Throughout the concert I felt like the rests weren't given enough time to make an impact; I didn't like the way he launched into the first movement of op. 111 the second he sat down at the keyboard (the audience was still settling down after an intermission); I wasn't often touched, and there just seemed a lot more to admire than to love about the playing and interpretation. Yes, it's very well thought out (no surprise there) and logical and orderly and still....there was something missing.
For other views, Rich Scheinin of the Mercury-News was very unhappy with the previous evening's concert in San Jose; Renato Rodolfo-Sioson has a thoughtful review of the lecture and concert in San Francisco Classical Voice.