Actress and singer Lady Gaga has heaped praise on her award-winning co-star Joaquin Phoenix, who plays the title role in “Joker: Folie à Deux” and talked about what was so special about his performance for her the first time.

Joker: Folie à Deux. The 60-second video features Lady Gaga's Harley Quinn visiting an emaciated Arthur Fleck, or Joker, played by Joaquin Phoenix, who is in a mental institution. Before she leaves, she pulls out a red lipstick and smears a clownish grin,

Lady Gaga recently shared the movie's final trailer, and she sounds absolutely incredible singing "That's Life" in it. What we know about Joker: Folie à Deux is limited, but that'll change when it hits theaters in October.

A new Joker 2 clip is out, previewing the unconventional romance between Joaquin Phoenix’s Joker and Lady Gaga’s Harley Quinn in the upcoming DC sequel. What happens in the Joker 2 clip? The new clip sees Quinn visiting Arthur Fleck as he’s being held in jail.

That certainly looks to be the idea in the latest trailer for Todd Phillips all-singing, all-dancing movie with music Joker: Folie À Deux, which sees Joaquin Phoenix's Arthur Fleck taking to the stand as he goes on trial for the televised killing of Murray Franklin (Robert De Niro) in Joker.

Whether or not the cast and crew consider Joker 2 to be a musical, casting Lady Gaga in a role that's both dramatic and requires singing feels like a brilliant choice. What's more, it seems like she and Joaquin Phoenix really matched each other's energy on set.

Lady Gaga is already making naysayers eat their words with just the teaser of Harley Quinn in Joker: Folie à Deux.