Danijela Kulezic-Wilson has discussed at length how the use of music in cinema adds to its corporeality and both fleshes out and gives life to otherwise spectral images. Todd Philips’ Joker (2019) both narratively and aesthetically leverages music to embody Arthur Fleck’s (Joaquin Pheonix) transformation from outcast to popular villain. In a Q&A with The Academy, Philips described the character of Fleck as full of grace and someone who “has music in him”, and it is Fleck’s performative interaction with the music as he becomes the Joker that leads to the corporeal reading of the film presented in this article. At the beginning of the film, Fleck is a thin and gaunt man, a ghostly figure lacking love or meaning, but he soon grows more bold and violent. Fleck’s horrifying acts of violence are accompanied by his bodily interaction with the music as he dances to both the soundtrack and the score as if it were emanating from him in some meta-diegetic sense. Joker is a deeply musical film, and its protagonist engages with both Hildur Guðnadóttir’s composed score and its compilation soundtrack, giving physical form to his metamorphosis. This paper investigates how musical moments and dance in Joker give corporeal form to Fleck’s alter ego and simultaneously encourage audience identification with its protagonist’s transformation.