Alex Ross’s capacious and enthralling new study, “Wagnerism: Art and Politics in the Shadow of Music,” is perfectly timed. Richard Wagner’s music, particularly that for his epic, doom-suffused opera, “The Ring of the Nibelung,” could easily supply our brutalist era with its big-screen soundtrack, starting with the exhilarating “Ride of the Valkyries” and closing with the orchestral Sturm und Drang of its over-the-top finale, in which celestial Valhalla goes up in flames, the Rhine River overflows its banks and the age of gods and heroes reaches its apocalyptic end.

Without serious competition, Wagner (1813-1883) is easily the most divisive of all the great composers. To some listeners, his music sounds bombastic, long-winded and boring 90 percent of the time — and yet redeemed by the sheer wonder and transcendent beauty of that remaining 10 percent. Other listeners worship, if only metaphorically, at Bayreuth, Germany — long the home of an annual Wagner festival — like so many Parsifals genuflecting before the Holy Grail. Yet still other opera devotees, aware of Wagner’s anti-Semitism, refuse to listen to his music at all. It doesn’t help either that the so-called “Sorcerer of Bayreuth” was the favorite composer of the Third Reich’s unspeakable Fuhrer.

While I myself am hardly “The Perfect Wagnerite” — as Bernard Shaw titled his monograph interpreting the “Ring” as a parable of class struggle — I have seen two different stagings of “The Flying Dutchman,” own CDs of the major operas, can never quite remember whether “Here Comes the Bride” rings forth in “Lohengrin” or “Tannhauser” (it’s “Lohengrin”), and find that even now my pulse races and my palms break out in a sweat whenever I hear the Love Duet or the Liebestod — that ecstatic vision of love after death — from “Tristan und Isolde.”

I first discovered Wagner, indeed discovered opera, through “Tristan.” I still remember feeling slack-jawed with amazement as Ludwig Suthaus and the electrifying Kirsten Flagstad, in a celebrated performance directed by Wilhelm Furtwängler, finally surrender to their aching love for each other and almost literally sing their hearts out, their voices intertwining, sobbing, soaring as the two are carried away by wave upon wave of overpowering desire, their rapturous transports finally climaxing in soul-shattering cries of release, while the full orchestra blankets the ill-fated lovers with crescendos of voluptuous sound. In that little record-listening booth at the Oberlin Conservatory of Music, I quickly understood why Victorian mothers refused to allow their daughters to hear such music. This wasn’t just a 40-minute duet, it was aural sex.

Alex Ross’s first book, “The Rest Is Noise: Listening to the Twentieth Century” (2007) garnered widespread praise while his second, “Listen to This” (2010), assembled various columns from the New Yorker magazine, where he is music critic. Ross tells us that he began work on “Wagnerism” in 2008, adding that the extensive research for this cultural history of “art and politics in the shadow of music” became the major educational experience of his life.

In “Wagnerism,” the reader will duly find a potted biography of the composer and, scattered throughout, synopses of his operas, but mainly this is a far-ranging survey of how various people and institutions responded to Wagner’s music and used it for purposes of their own. In these 700-plus pages you will learn what Wagner meant to Nietzsche and Baudelaire, to the modernists James Joyce, T.S. Eliot, Willa Cather and Thomas Mann, to 19th-century occultists, symbolist painters, pioneering feminists and gay poets, to revolutionary Russians and Nazi apologists, and even to the Hollywood visionaries of “Apocalypse Now” and “Star Wars.”

Wagner’s exceptionally lively afterlife derives not only from, in Cather’s phrase, his “ever-darkening, ever-brightening” music, but also from his use of multivalent symbolism, especially in the ‘Ring” cycle’s “Das Rheingold,” “Die Walkure,” “Siegfried,” and “Gotterdammerung.” In 2020, for instance, these music dramas seem to anticipate the political turmoil of recent times, as they track the thefts and shady deals that lie behind excessive wealth, the ethical impairment resulting from the hunger for power, the heartless exploitation of an underclass, murderous intergenerational conflicts, the flouting of sexual prohibitions and, more than anything else, repeated betrayals of trust.

To create this dark vision of “the Twilight of the Gods” Wagner drew on Northern myths, the medieval revenge epic, “Das Nibelungenlied,” and wintry tales of the Norse god Wotan, Siegfried the Dragon-Slayer and Brunnhilde the Valkyrie. Ross points out that the composer himself appears to have invented that key object of modern fantasy, the accursed ring of unimaginable power. What’s more, Wagner’s libretto is a work of literature, as witness a majestic bilingual edition available this fall from the Folio Society.

Throughout his book, Ross draws on the research of numerous scholars and specialists (always acknowledged) and quotes well from his older sources. John Ruskin described the comic opera “Die Meistersinger von Nurnberg” as “sapless, soulless, beginningless, endless, topless, bottomless.” To knit together the elements of “In Search of Lost Time” Proust employed Wagner-style leitmotifs, such as a haunting musical phrase by his imaginary composer Vinteuil. Speaking of Siegfried, Ross himself wittily concludes, that “stupidity is his tragic flaw.” He calls “Parsifal” a “sacred opera with a spooky heart,” links its eerie Mass-like ritualism to the esoteric ceremonies of Theosophists and Rosicrucians and notes that Philip K. Dick responded profoundly to its religious syncretism. A chapter on early Black Wagnerians includes that ardent Germanophile, W.E.B. Du Bois.

In Wagner’s operas, sums up Ross, “we see the highest and the lowest impulses of humanity entangled.” In “Wagnerism,” however, those impulse — aesthetic, sexual, philosophical and political — are deftly untangled, then enticingly presented for the general reader. The result is a superb example of cultural history and, given its themes, a work surprisingly relevant to this plague-ridden, watershed year.

Michael Dirda reviews books for Style every Thursday.

Wagnerism: Art and Politics in the Shadow of Music

By Alex Ross

Farrar Straus Giroux. 769 pp. $40