Spoilers for Joker below:
It turns out that one key scene from Joaquin Phoenix’s Joker movie was basically filmed in the spur of the moment, with the help of some new music from the film’s composer.
In Joker, following a pivotal scene that alters the course of Arthur Fleck’s life, Fleck flees to a grungy park restroom where he attempts to collect his thoughts. In an interview with Screenplayed, director Todd Phillips says that the original script for this scene showed Fleck hiding his gun, washing off his makeup, and staring at himself in the mirror while reflecting on what he’s just done.
Source: IGN.com Joker Director Reveals How the Score Changed That One Key Scene