Lady Gaga is revealing how she changed her singing voice for her version of Harley Quinn (aka Lee) in Joker: Folie À Deux.

The Oscar and Grammy winner, who stars opposite Joaquin Phoenix in Todd Phillips‘ musical sequel, recently opened up to Empire magazine about how her singing in the movie was “unlike anything I’ve ever done before.”

“People know me by my stage name, Lady Gaga, right? That’s me as that performer, but that is not what this movie is; I’m playing a character,” she explained. “So I worked a lot on the way that I sang to come from Lee and to not come from me as a performer.”

The A Star Is Born actress knew the music in the film needed to be treated with care, given that it was going to be incorporated into the storyline.

“How do you take music and have it just be an extension of the dialogue, as opposed to breaking into song for no conceivable reason?” Gaga asked. “It was unlike anything I’ve ever done before.”

This led the “Shallow” singer to explore a different side of her as a performer — one that fans have never seen before.

“For me, there’s plenty of bum notes, actually, from Lee,” she said, with a laugh, of her singing voice in the movie. “I’m a trained singer, right? So even my breathing was different when I sang as Lee. When I breathe to sing onstage, I have this very controlled way to make sure that I’m on pitch, and it’s sustained at the right rhythm and amount of time, but Lee would never know how to do any of that. So it’s like removing the technicality of the whole thing, removing my perceived art form from it all and completely being inside of who she is.”

Joker: Folie À Deux, a follow-up to 2019’s Oscar-winning Joker, sees failed comedian Arthur Fleck (Phoenix) meet the love of his life, Harley Quinn (Gaga), while incarcerated at Arkham State Hospital. Once he’s released, the duo embarks on a doomed romantic misadventure.

Phillips also explained to Empire how Gaga’s take on the legendary character is different from previous iterations of Harley Quinn.

“While there are some things that people would find familiar in her, it’s really Gaga’s own interpretation, and Scott [Silver, co-writer] and I’s interpretation,” the filmmaker added. “She became the way how [Charles] Manson had girls that idolized him. The way that sometimes these [imprisoned murderers] have people that look up to them. There are things about Harley in the movie that were taken from the comic books, but we took it and molded it to the way we wanted it to be.”

Joker: Folie À Deux is set to hit theaters Oct. 4.