Nick Cave features on the official soundtrack for Joker: Folie à Deux, sharing a medley of “Slap That Bass,” “Get Happy,” and “What the World Needs Now Is Love”. Lady Gaga also unveiled a companion album, Harlequin.

Speaking to Zane Lowe about the release, she said: "I was always creating characters in my music and when I made Lee for Joker, she just really had this profound effect on me," she continued. "The film had so much music in it, so much music that I love, and I was able to discover the character through the story, through the music that we did live every day as well as dance and the costumes and the makeup. So I kind of had this deep experience with the character and she just didn't really leave me creatively and I decided I wanted to make a whole album inspired by her."