Sometimes short books on great musicians markedly surpass longer ones. Aspects of Wagner, by British philosopher and ex-parliamentarian Bryan Magee, provides a much better guide in its 112 pages to the Master of Bayreuth than do most other Wagner-related books of seven times the size. Similarly, Edmund Morris’s 2005 Beethoven: The Universal Composer (256 pages, all spaciously printed) contains far more genuine discernment than numerous scholarly marathons. And so with this latest concise publication by the Cleveland-born, now Manhattan-based, and for long Italian-domiciled Harvey Sachs. Sachs’ earlier works include comprehensive biographies of Toscanini and Artur Rubinstein, as well as a piercingly perspicacious 1982 essay on Glenn Gould (which concedes all Gould’s pianistic virtues while exposing, with quiet mercilessness, Gould’s fundamentally adolescent philosophizing). Any music lover—no matter how well he knows, or thinks he knows, Beethoven’s Choral Symphony—will learn something new from Sachs’ account, which is neither pure musicology nor pure aesthetic rumination, but a fascinating mixture of both. Herbert von Karajan’s comment on Beethoven’s symphonies in general accords with Sachs’ attitude: “They become younger and younger every day; and the more you play them the more you know you can never get to the bottom of them.” Sachs...