Oscar-winner Lady Gaga is allegedly in early talks to play Harley Quinn in 'Joker.

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'Joker: Folie a Deux,' a musical sequel to director Todd Phillips' 2019 movie 'Joker.'

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Last week, the filmmaker confirmed the sequel to 'Joker' in an Instagram post.

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Also revealed that Joaquin Phoenix is expected to reprise his role as the Joker.

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Sources told The Hollywood Reporter that the sequel is also a musical.

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Past Warner Bros' projects have seen Margot Robbie and Kaley Cuoco star as Harley Quinn.

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When the director teased the script of 'Joker: Folie a Deux,' written by him and Scott Silver, rumors were that Harley Quinn would be a part of the follow-up.

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Phillips was a producer on Lady Gaga's 2018 film 'A Star Is Born,' which won her an Oscar nomination for Best Actress and a victory for Best Original Song.

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The film also won an Oscar for Best Original Score for Hildur Guonadottir.

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