A few summers ago, the German Chamber Orchestra of Bremen came to town, giving a concert at the Mostly Mozart Festival. And the excellent critic Anne Midgette, then of the New York Times, now of the Washington Post, opened her review this way: “The future of classical music is a hot topic these days. Plenty of us hold forth about the need for more new works, more variety, a more contemporary flavor.” But what the Bremen orchestra provided was “an all-Beethoven concert with some of the most traditional, oft-played repertory in the book”: the Coriolan Overture, the Violin Concerto, and the “Eroica” Symphony. “And what do you know? The crowds reached from Alice Tully Hall to the corner, and many were turned away disappointed. It looked like the event of the summer. Which should remind some of us that one thing the classical music audience does want is classical...