Lady Gaga discussed this subject while explaining how the movie inspired her new album Harlequin, which collects reimagined covers that she and Phoenix sing in Joker, as well as two original songs. The singer-songwriter and star of movies like A Star is Born and House of Gucci started off by telling EW:

The Oscar-winning singer stars opposite Joaquin Phoenix in the upcoming sequel as the disturbed lover of his titular Batman villain.

In 2019, “Joker” became an improbable box office smash and cultural juggernaut. Sure, the R-rated crime drama was based on the ubiquitous Batman villain. But this take on the Clown Prince of Crime was darker and more disturbing than your average comic book adaptation - more akin to Martin Scorsese’s “Taxi Driver” than the DC

Lady Gaga has announced a brand new album called Harlequin, with the project serving as a companion piece to Joker: Folie à Deux. The upcoming movie, a sequel to the 2019 film, sees Joaquin Phoenix reprise his role as Arthur Fleck, with the character meeting Harleen ‘Lee’ Quinzel (Gaga) during his stint at Arkham State Hospital.

Lady Gaga, whose real name is Stefani Joanne Angelina Germanotta, is set to portray one of pop culture’s most iconic characters, Harley Quinn.

The singer, who announced that she will be dropping the first single from her forthcoming seventh studio album next month, just announced “Harlequin,” a soundtrack album titled to the forthcoming film “Joker :Folie et Deux,” in which she stars with Joaquin Phoenix.