The unruly and elusive entity known as classical music does not sound like any one thing, and the sheer abundance of the tradition might invite the conclusion that trying to define it at all is a hopeless exercise. But that would be a mistake, especially at this moment. Like every other sector of cultural life, classical music has been roiled over the past decade by intense debates about the field’s ongoing lack of diversity, among performing artists, composers, and leaders of musical organizations. The stakes of these discussions—which have involved charges of Eurocentrism, head-in-the-sand elitism, even white supremacy—have at times felt existential, given many institutions’ financial straits. Maintaining a 90-piece orchestra is generally a money-losing proposition in America today, and as a result, classical-music organizations lean heavily on private donations. Why, many onlookers have asked, should an orchestra or opera company gobble up millions of dollars from wealthy sponsors to subsidize the salaries of musicians who mainly perform music by white men from centuries past, music for which (judging by ticket sales) demand is limited? What is classical music, whom is it for, and what about it is worth defending?