NEW YORK, NY.- On the HBO costume drama “The Gilded Age,” Kelli O’Hara plays a New York grande dame forced to choose sides in an opera war: remain at the old guard’s Academy of Music or defect to the Metropolitan Opera being built by the nouveau riche they had excluded.

When her character, Aurora Fane, joins a throng of socialites surveying the nearly completed Met, the camera lingers on her face, upraised in awe.

O’Hara herself is far more familiar with the Met, at least in its current incarnation. In addition to being a Tony-winning star of Broadway musicals and an Emmy nominee, she has been singing at the Met for nearly a decade and is back now for a revival of “The Hours,” starring opposite Renée Fleming and Joyce DiDonato, opera legends both.

Still, the Met’s grand auditorium, which holds 4,000 people, inspires the same wonder in O’Hara as it does in Aurora. Although Aurora never had to fill it. And O’Hara does.

“Once I give over to it and believe in myself, I remember that this is the way my voice wants to sing,” she said.

This was on a recent morning during a break from rehearsals. O’Hara, 48, had traded her costume corset for a black jumpsuit. One hand held a paper cup of coffee. (A socialite would never.) Later she would return to the basement space where she is rehearsing “The Hours,” Kevin Puts’ adaptation of Michael Cunningham’s time-skipping novel, itself inspired by Virginia Woolf’s “Mrs. Dalloway,” which opens Sunday.

One of the Met’s archivists, John Tomasicchio, stopped in to show O’Hara a few items from the Met’s founding that would have been familiar to Aurora: a piece of its original stage, an etched glass lightbulb, brocade from a box seat. Tomasicchio displayed a newspaper illustration of the audience thronging the stage.

“It was like a rock concert,” O’Hara marveled. “The passion people had.”

Opera was not quite O’Hara’s first passion. She went to college intending to study musical theater but was told that her voice wasn’t built for the pop and rock styles then in vogue. As she was graduating, she participated in the Met’s National Council Auditions and made it to the finals at the regional level. But she missed the camaraderie she had experienced in musical theater, so she packed her bags and headed for Broadway.

Broadway welcomed her. She starred in acclaimed productions of classic musicals including “South Pacific” and “The King and I,” for which she won a Tony. Just this week she received her eighth Tony nomination for “Days of Wine and Roses.”

While she did not regret leaving opera, she sometimes wondered how she might have fared on the Met’s stage. “There was always this thing in the back of my head that said: But my voice wants to sing that way,” she said.

At the very end of 2014, she had her chance, in a new production of the operetta “The Merry Widow” directed by Susan Stroman, with whom she had previously worked on Broadway. She followed that debut with a production of Mozart’s “Così Fan Tutte” in 2018. To make this leap in midcareer was frightening, but O’Hara, who runs marathons and has gone sky-diving, doesn’t mind a certain amount of fright.

“I had to put my backbone straight and have conversations with myself,” she said. “‘You can do this. You’re fine. Just keep your nose to the ground and do your work.’”

That work paid off. When she sang in “Così,” her “lovely soprano voice and quite good Italian diction” were praised by Anthony Tommasini of The New York Times.

While opera singers occasionally make the move to Broadway (Fleming and Paolo Szot are recent examples), careers rarely flow the other way. And a performer who can do all this and television, too? That’s rarer still.

“The Hours,” O’Hara’s first contemporary opera, which premiered in 2022, is a further challenge. O’Hara co-stars as Laura Brown, a woman constrained by the suburban rhythms of post-World War II California. In some ways, Laura is a companion to Kirsten, the role O’Hara was nominated for in Adam Guettel’s “Days of Wine and Roses.” Kirsten is another woman confined by the expectations of midcentury American life. Both find freedom where they can.

“I’m coming off of over two years now of playing sad women, held women — even Aurora, held back, constricted,” O’Hara said.

For O’Hara, opera is not exactly freeing. It’s too demanding for that, too needful of perfection. But she believes that she’ll keep pursuing it — for the difficulty, for the terror, for the range of roles. (On TV, she said, she now plays grandmothers. Opera is rather more forgiving.)

O’Hara knows that she could fail. Her voice could crack. She might flub a note. But Aurora is brave enough to join the new-money mavens at the Met’s opening. And O’Hara in her way is brave, too. Brave enough to send her bright, unamplified soprano out into thousands of ears each night.

“I’m confident enough to want to try,” she said.

This article originally appeared in The New York Times.