Carey Mulligan Says Bradley Cooper Began Speaking Like Leonard Bernstein 'A Full Year' Before Filming “Maestro”

Carey Mulligan called Bradley Cooper's prep work to play the late composer Leonard Bernstein in 'Maestro,' which releases on Netflix Dec. 20, "astonishing"

Carey Mulligan was surprised by the amount of work Bradley Cooper put in to embody Leonard Bernstein in their new movie.

As Mulligan, who plays the late composer Bernstein's wife Felicia Montealegre in Netflix's upcoming drama Maestro, spoke with Variety about the biopic, she said Cooper, 48, conducted "mammoth amounts of research and preparation in all aspects" as he wrote, directed and acted in the film.

"We really rehearsed it like a play. We had so much prep," she said. "We also spent a week together doing a specific workshop just on our two characters — just Bradley and I digging into who Lenny and Felicia were, and how that connected to us."

Mulligan said that she has "never seen anyone prep for a character the way that [Cooper] prepped for Lenny."

"It was astonishing. He was ringing me up in the full dialect a full year before we even got to New York," she told the outlet. "I mean, it was unbelievable. By the time we were shooting it, it just didn’t feel like we had to think very much. And I think it was the sort of not having to think about it that made it very easy to just respond to stuff."

Related: Bradley Cooper Asked Carey Mulligan to 'Bare Our Souls to Each Other' as Prep for Maestro Roles

Maestro's makeup designer Kazu Hiro previously revealed the the production "made a nose plug" for Cooper to wear inside a prosthetic nose he used in order to look and sound more like Bernstein, who died at 72 in 1990. Maestro primarily follows the famed composer's romance and marriage with Montealegre, which lasted from 1951 until her death in 1978.

An official logline for the movie describes Maestro as "a towering and fearless love story chronicling the lifelong relationship between Leonard Bernstein and Felicia Montealegre Cohn Bernstein." 

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Maestro marks Cooper's second feature-length film as a screenwriter and director, in addition to his already impressive acting career. Cooper also notably went to great lengths to alter his voice for 2018's A Star Is Born: he told Entertainment Weekly that year that he sought to "lower my speaking voice an octave" in order to play the fictional rockstar Jackson Maine.

Related: Leonard Bernstein's Daughter on 'Surreal' Experience Seeing Maestro Film About Her Family: 'What a Ride'

"So I hired [dialect coach] Tim Monich early on — I mean, like, a year before we shot the movie," Cooper shared at the time. "He moved to L.A. and we worked five days a week, four hours a day on exercises and lowering my voice. It was brutal, and it took months and months and months."

Cooper also shared during his A Star Is Born press run that he utilized his costar in the movie, Sam Elliot, as a reference point for how low he wanted his voice to sound. During a Feb. 2019 appearance on The Late Show with Stephen Colbert, Cooper even said he worked at changing his voice for A Star Is Born so much that he "would go to sleep and my throat would hurt."

Maestro will run in select theaters in November before it hits Netflix on Wednesday, Dec. 20.

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