For more than a century now, Richard Wagner’s Der Ring des Nibelungen, finally completed in 1876, has constituted the supreme test of an opera company’s greatness. Other operas—among them the remaining six of Wagner’s major works—are difficult to do, as well as important. But despite all the challenges presented by such composers as Mozart, Verdi, and Strauss, and by Wagner’s own Tristan und Isolde and Die Meistersinger, both the immensity and the seriousness of the Ring place it in a class by itself.

It is easy to see why this should be so. The Ring takes four evenings to perform, and in its constituent parts—Das Rheingold, Die Walküre, Siegfried, and Götterdämmerung—presents a myth of the creation, and the destruction, of the world. As he did with his other operas, Wagner wrote the book of the Ring himself, drawing on Norse mythology but at the same time performing miracles of integration, concision, and clear exposition.

It is not simply that Wagner projected his view of the beginning and end of the world. And it is not simply that he peopled that world with gods and their runaway human offspring, with giants and dwarfs, with miracles and catastrophes. Wagner claimed his high place in the making of modern mythology by the creation on a colossal scale of all-too-believable characters motivated almost solely by greed, lust, and treachery. It is not that all Wagner’s creations were so motivated: in Wotan’s goddess daughter Brünnhilde, and