NEW YORK – Before she could play an opera legend, Angelina Jolie had to find her voice.

The A-lister threw herself into new movie "Maria," undergoing seven months of rigorous vocal training to embody Greek opera star Maria Callas in the upcoming Netflix film.

When Jolie first signed on, "I thought, 'Oh, I'll pretend-sing and I'll get through this,' " she recalled Sunday during a post-screening Q&A at the movie's New York Film Festival premiere. "Then it was very clear to me that you can't pretend opera, and then I was scared."

The film is directed by Pablo Larraín, who helped guide Natalie Portman and Kristen Stewart to best actress Oscar nominations playing Jacqueline Kennedy (2016's "Jackie") and Princess Diana (2021's "Spencer"), respectively. "Maria" is the ending of a trilogy for the director, who imagines all three women as caged birds breaking free.

Join our Watch Party! Sign up to receive USA TODAY's movie and TV recommendations right in your inbox.

Need a break? Play the USA TODAY Daily Crossword Puzzle.

A fan of opera since childhood, Larraín was intrigued by the idea that Callas frequently died onstage at the end of her productions, but she had no fear of death in her personal life. As the film depicts, she lived a secluded existence in her final years and often resisted medical attention. She died in 1977 at age 53 of a heart attack, after struggling with substance abuse and the loss of her voice.

Initially, Larraín envisioned Callas as a more "tragic" figure. But "when Angie came in, she brought something that I immediately accepted: this sense of stoicism," he said. "I would say, 'Could you be broken here?' And she would say, 'No, I think she's stronger than that.' So we built this character who, even going through the darkest times, is always in command. She's never a victim."

"Maria" flashes back and forth between Callas' last days and younger years, tracing how her mother pushed her into show business and how she was silenced by her longtime partner, Aristotle Onassis (Haluk Bilginer), who later left her for Jackie Kennedy. Despite Callas' suffering, Jolie imbues her with a crackling wit and a diva-like yearning to be adulated.

"When I see someone who's so full of self-pity or giving up, it doesn't move me in the same way," Jolie, 49, explained. "She would try to pull herself together and move forward. I wanted this to be about what an extraordinary artist she was – she was a fighter and a deeply feeling, emotional person."

That unflagging spirit helped inform Jolie's vocal performance in the movie. The Oscar winner's voice is mixed with real recordings of Callas. But it was important to Larraín that she was actually singing live on set, in order to ensure that her movements and breathing would mimic those of a trained prima donna.

"For anybody here who hasn't sung at the top of their lungs, it's a crazy thing to do," Jolie said. "We never do it; we never know what it's like to be fully in your body at your fullest sound. It's such an extraordinary thing to feel as a person, to know what you've got inside of you. I'm very lucky I had all these teachers and people supporting me to say, 'Let's hear your full voice.' It really meant a lot to me as a person."

Jolie was supported at Sunday's premiere by three of her kids – Maddox, 23, Pax, 20, and Zahara, 19 – as well as Broadway director Danya Taymor, who collaborated with the actress on this year's Tony-winning musical "The Outsiders." "Maria" may well land Jolie her third Oscar nod, after winning for 1999's "Girl, Interrupted" and getting nominated for 2008's "Changeling."

The film opens in theaters Nov. 27, before streaming on Netflix Dec. 11.