Young singers usually wait many years before tackling Wagner, but Astrid Varnay showed prodigious maturity while she was still in her early twenties. Photograph by Ullstein Bild / Getty

Two of the greatest dramatic sopranos of the twentieth century were born in Sweden a century ago, within a few weeks of each other. The first to arrive was Astrid Varnay, on April 25, 1918; after her, on May 17th, came Birgit Nilsson. Both must have made an impressive noise when they first saw the light of day. Scandinavia has a long history of cultivating powerful Wagnerian voices: before Varnay and Nilsson, it produced Kirsten Flagstad, Olive Fremstad, Nanny Larsén-Todsen, and Kerstin Thorborg, and the tradition continues today with the Swedish sopranos Nina Stemme and Iréne Theorin. (The latter is about to sing Brünnhilde in three cycles of Wagner’s “Ring” at the San Francisco Opera.) It has been theorized, dubiously, that Nordic artists acquire an early knack for hollering across wide-open spaces. But Varnay was Swedish only by happenstance; her parents were itinerant Hungarian opera people, and within several years the family had made its way to the New York area. The conjunction of Varnay and Nilsson is a freak instance of once-in-a-lifetime singers appearing in the same place at the same time.

Nilsson has found more favor with posterity. Her centenary is being celebrated in lavish style, with a monumental coffee-table book titled “Birgit Nilsson: 100”; a documentary, “Birgit Nilsson: A League of Her Own”; and a seventy-nine-CD set from the Decca label, with another boxed set arriving in the fall from Sony Classical. The documentary opens with a scene from “The Golden Ring,” a 1965 BBC film about the first complete studio recording of the “Ring.” Nilsson is seen singing Brünnhilde’s climactic monologue in “Götterdämmerung.” Just as the Valkyrie is hailing her horse Grane, an elegant Viennese equine is led in—a prank overseen by John Culshaw, the producer of the project. Nilsson looks up in surprise; beams with delight, gesturing toward the horse; and goes on singing at full force, even as the orchestra collapses in laughter. No soprano could match her stamina, and with her down-to-earth personality she managed the feat of making Wagner seem wholesome.

With Nilsson in no danger of disappearing, let’s blow the steerhorn for Varnay, whose centenary came and went with little fanfare. Although she couldn’t match Nilsson’s technical security, she is my favorite among the Very Loud Ladies—the one in whom musical and dramatic values are most evenly balanced, the one whose interpretive intelligence is most acute. If I could travel back to the mid-century golden age of Wagner singing, I would go to Bayreuth in 1953, when Varnay was portraying Brünnhilde, Isolde, and Ortrud. In those years, Wieland Wagner, the composer’s grandson, had stripped the stage of familiar scenic clutter, presenting a radically abstracted image. When he was questioned about the practice, he would ask, “Why do I need a tree on the stage when I have Astrid Varnay?”

Violet Varnay, as she was known in her American youth (Astrid was her middle name), initially intended to be a pianist, but she turned to singing when she was a senior at William L. Dickinson High School, in Jersey City. She studied with, and later married, Hermann Weigert, a German Jewish émigré conductor. Young singers usually wait many years before tackling Wagner, but Varnay showed prodigious maturity while she was still in her early twenties, and, on December 6, 1941, she made one of the most sensational débuts in the history of the Met, substituting for Lotte Lehmann as Sieglinde, in “Die Walküre.” This was, in fact, her first performance on any operatic stage, as the Times’ review noted with wonder. The occasion was broadcast on the radio, and the recording makes her virtues clear: confident phrasing, incisive diction, a constant dramatic pressure. Here you can listen to an audio excerpt of Sieglinde’s sublime cry of “O hehrstes Wunder! Herrliche Maid!” (“O noblest wonder! Glorious woman!”). In her memoir, “Fifty-five Years in Five Acts,” Varnay tells of how her brother went out the following day to look for reviews, and returned with the news of Pearl Harbor.

Varnay seemed destined for a long reign as a Met star, but Rudolf Bing, who took over as the company’s general manager, in 1950, failed to capitalize on her talent, and so she turned her attention to Europe. Kirsten Flagstad, who had known Varnay since she was a child, recommended her to Wieland Wagner when Bayreuth resumed operations in 1951. (You can hear the two singers face to face in a Met “Walküre”; Flagstad goes first, then Varnay salutes her as a “herrliche Maid.”) For more than a decade, Varnay would co-own the role of Brünnhilde at Bayreuth, sharing it first with Martha Mödl—another great singing actress—and then with Nilsson. In the same period, Varnay delivered scalding performances of the title roles in Strauss’s “Salome” and “Elektra.” She recorded both operas in the summer of 1953, before and after Bayreuth. No singer can have the last word on such demanding parts, but Varnay comes close to mastering them all. The one that slightly eludes her is Isolde. Flagstad was past her prime when she recorded “Tristan” with Wilhelm Furtwängler, in 1952, yet the courtly warmth in her voice supplies a dimension lacking in Varnay’s tour de force of raging passion.

By rights, Varnay should have appeared in the first stereo recording of the “Ring.” Unfortunately, record-company politics foiled plans to document one of the mighty Bayreuth casts of the early and mid-fifties. Decca recorded the “Ring” of 1955, with Joseph Keilberth conducting, but it never saw the light of day. Culshaw took over as Decca’s senior producer, in 1955, and it is thought that he discouraged release of the tapes because he was plotting his own studio version of the “Ring.” That epic project, under the musical direction of Georg Solti, got under way in 1958, and was completed in 1965. Selling many thousands of copies, it defined Wagner singing in the minds of the broader public. The Brünnhilde of record was Birgit Nilsson.

Admittedly, by the mid-sixties Nilsson was the right choice for the part. The big Wagner and Strauss roles can take a toll, and Varnay showed increasing signs of strain. Her access to top notes was never as easy as it was for Nilsson, who knocked them off like Ty Cobb in a batting cage, and her upper register grew unstable and shrill. In the same years, Nilsson was reaching her peak; she had wisely followed a more gradual path of development, and did not take up Wagner until the late nineteen-forties. (In her memoir, “La Nilsson,” the soprano comments that, at the age Varnay made her Met début, she was still pulling up carrots on her parents’ farm.) Nilsson is the glowing core of the Culshaw “Ring.” When she awakens in Act III of “Siegfried,” her exclamation “Heil dir, Sonne!”—“Hail to you, sun!”—has itself the effect of sunlight falling on the senses, a beam of heat.

Yet when people ask me which “Ring” they should own, I recommend the 1955 Bayreuth recording, which finally had an official release, in 2006 and 2007, courtesy of Testament Records. Varnay is hardly the only reason to have it: Hans Hotter is a majestically anguished Wotan, and Wolfgang Windgassen’s rugged Siegfried sounds fresher than it does on the Culshaw “Ring.” Keilberth is a subtler, more expressive conductor than Solti, who too often lets the brass section devolve into brutal blaring. As for Varnay, she captures the teeming complexity of Wagner’s Brünnhilde, who is at various times an obedient warrior, a rebellious daughter, a besotted lover, an enraged wife, and, at the end, a philosopher of world revolution. Varnay’s “Heil dir, Sonne!,” with its scoops and swells, is a bit more effortful than Nilsson’s, but its darker coloring immediately establishes Brünnhilde’s mood in this act: she is at once thrilled and terrified that a man has disturbed her slumber behind the ring of fire.