Charles Rosen is a brilliant writer about music. But he’s also a major pianist. “He would probably be better known as a pianist if he had not published a single word about music. That he has not belonged to the most visible group of concert pianists that includes Murray Perahia, Emmanuel Ax, Alfred Brendel, Maurizio Pollini, and Richard Goode is a circumstance with multiple causes (including his decision to play Boulez rather than Brahms, Schoenberg and Carter rather than Schubert and Copland).” So his new book about the piano is something to be taken very seriously indeed.