Karita Mattila has noticed something curious lately. When her rehearsals run longer than those of junior colleagues, they tend to stick around and watch. “It brings to mind when I was a student, doing master classes with the great stars or just being in the audience,” she says. “I remember everything those legends said and did. In the 37 years I’ve been in the business, I’ve had a fantastic number of awesome conductors and directors with whom I’ve learned a lot and achieved wonderful results. So I have a lot to give.”

At a time when a veteran diva might well wish to ease into glamorous semi-retirement—holding court at those master classes and doling out select appearances in opera houses that covet “luxury” casting—Mattila’s foreseeable future looks nothing like that. For the past five years, an assortment of debuts in plum roles have dominated her datebook: Marie, common-law wife to the psychotic antihero of Berg’s Wozzeck; Ariadne, abandoned by Theseus after saving him from the Minotaur, in Richard Strauss’s Ariadne auf Naxos; the imperious Foreign Princess in Dvořák’s poisoned fairy tale Rusalka; the war bride Sieglinde in Wagner’s Die Walküre, swept off her feet by her long-lost twin brother; the arch-carpetbagger Leokadja Begbick in Rise and Fall of the City of Mahagonny, the savage but tuneful takedown of capitalism by Kurt Weill and Bertolt Brecht …

“I have a lot to give.”

“I’ve done my share of certain roles,” says the Finnish singer, who as a new face shot straight to the top on the strength of her shimmering-silver soprano, her movie-star allure, and theatrical instincts as true in froufrou as in tragedy of the deepest dye. “And now there are wonderful new doors to open. I always had faith that everything would come naturally. Maybe that sounds naïve. But it’s happening. People ask me to do these roles, and I say, Why not?” Last year at the Canadian Opera Company, for instance, she created the role of the phantom empress Plotina in the world premiere of Hadrian, composed by the opera-mad, alternative-pop phenom Rufus Wainwright. The New York Times deemed Wainwright’s effort “exasperating,” but thought the aria for Plotina “wonderful.”

Mattila performs in Rise and Fall of the City of Mahagonny at 2019’s Festival d’Aix, in Aix-en-Provence, France.

For the most part, though, Mattila is remaining well within the canon. From pure young heroines who are victimized or falsely accused she’s moving on to the indomitable, morally ambiguous older women who drive their tragedies. Good-bye to the sore-tested Jenůfa of Janáček’s drama of infanticide—hello to the Kostelnicka, Jenůfa’s rectitudinous stepmother. This fall, in Wagner’s chivalric Lohengrin, Mattila transitions from the beleaguered Elsa, on trial for fratricide, to the demonic Ortrud, inventor of the slander. And next spring she returns to Richard Strauss’s Elektra, this time not as the protagonist’s virginal sister, desperate to have children, but as the sisters’ mother Klytämnestra, who butchered their father Agamemnon in his bath.

As a new face, Mattila shot straight to the top on the strength of her shimmering-silver soprano and movie-star allure.

Unlike Helen Mirren, say, or Meryl Streep, who can age for the limelight and swap personae at will, a diva in opera has her characters’ top notes to think about. Klytämnestra is forgiving that way—the part is written for the lower voice of a mezzo-soprano or even lower contralto. The same is much less true, if at all, of Mattila’s other late acquisitions to date.

In fact, to universal amazement, and throwing caution to the wind, Mattila has put the opera world on tenterhooks with her recent announcement—on Twitter—that she has signed to sing the heroine of Tristan und Isolde, Wagner’s ecstatically death-haunted, rule-breaking paean to all-consuming love. That’s a big sing. Once upon a time, Wagnerians everywhere were clamoring for Mattila’s Isolde, and she gave every indication she would oblige. Then she blinked, and that was that. But after her Indian-summer Sieglinde, the idea took fire again. And while the “when” and the “where” are still under wraps, Mattila confirms it’s in her calendar. “Everything comes in its own time. This is my time to tackle Isolde.” —Matthew Gurewitsch