Entertainment Music Miley Cyrus Teaches Joaquin Phoenix About Lady Gaga in Hilarious Resurfaced Video from 2010 In the resurfaced clip, Phoenix pretends that he's well-versed in Gaga's songs like "Everybody Goes Up" and "Two Lashes at a Time" By Ilana Kaplan Ilana Kaplan Ilana Kaplan is a Senior Digital Writer/Editor at PEOPLE. They have been working at PEOPLE since 2023. Their work has previously appeared in The New York Times, Rolling Stone, Vanity Fair, Vogue and more. People Editorial Guidelines Published on April 11, 2024 01:00PM EDT Close Joaquin Phoenix once pretended he knew who lady Lady Gaga was. In resurfaced video from 2010 — two years after the pop star released her debut album The Fame — Miley Cyrus needed to school the Napoleon actor, 49, on who his future costar was. The "Flowers" singer, 31, was in her pre-Can't Be Tamed era when she was awestruck that Phoenix didn't know who Gaga, 38, was in a clip that appears to be from the non-profit To Write Love on Her Arms. But initially, the Beau Is Afraid star pretended he was well-versed in the A Star Is Born actress. Miley Cyrus and Joaquin Phoenix in 2010. TWLOHA/YouTube All About Joker: Folie à Deux Starring Lady Gaga and Joaquin Phoenix “You know who Lady Gaga is?” Cyrus asks Phoenix in the clips, to which he replies: “Very well." However, he then tries to convince her that he's well-versed in Gaga: “She has the song ‘Everybody Goes Up.’ She also does the one ‘Two Lashes at a Time.'” Cyrus calls his bluff and bursts into a seated song and dance to "Bad Romance," which Phoenix pretends to mimic at first, but then admits, “I don’t know that song.” Miley Cyrus at the 2024 Grammys on Feb. 4 2024; Joaquin Phoenix at the 'Napoleon' premiere on Nov. 20, 2023; Lady Gaga at the 2022 Grammys on April 3, 2022. Lionel Hahn/Getty; Borja B. Hojas/WireImage; Frazer Harrison/Getty Luckily, the Oscar winner now knows who the actress/pop star is as the pair are set to star opposite one another in Joker: Folie à Deux, the upcoming musical sequel to Todd Phillips' Oscar-winning 2019 film Joker. Appearing alongside Phoenix as the titular Batman villain, Gaga will take on the role of Harley Quinn. The forthcoming movie's first trailer was revealed on Tuesday, April 9 at CinemaCon in Las Vegas. In it, Gaga's Harley can be seen in what appears to be an insane asylum, meeting with Phoenix’s Arthur Fleck. “Do you want to get out of here?” she asks him, before the two can be seen dancing in a fantastical musical sequence. Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories. Lady Gaga and Joaquin Phoenix are seen on the set of 'Joker: Folie a Deux' at Shakespeare Steps in the Bronx on April 3, 2023 in New York City. James Devaney/GC Images Lady Gaga's Harley Quinn Meets Joaquin Phoenix's Joker in Folie à Deux Trailer Phoenix can be heard saying, “I’ll tell you what’s changed. I’m not alone anymore. That’s what we should be talking about!” Later in the trailer, Gaga's Harley says, “I want to see the real you,” drawing a smiley face with lipstick on the glass divider that separates them, as The Joker smiles. Joker: Folie à Deux is set to be released in theaters on Oct. 4, 2024.