With Joker following the protagonist Arthur Fleck's aspirations to become a standup comedian, one memorable sequence has Arthur loudly faking a laugh as he observes a successful stand-up set by real-life comedian Gary Gulman.
Gulman was approached by filmmaker Todd Phillips for the small role, receiving two pages of the script detailing his part with instructions to keep his routine period-appropriate to the film's 1980s setting. As Gulman was filming his scene for the film, he was irritated by someone in the audience laughing a bit too loudly and considered complaining to Phillips between takes. Little did Gulman know, it was star Joaquin Phoenix himself.
"When I was running through my set, there were all these extras, and they’d clearly been told that I was doing well, so they were laughing and enthusiastic. And there was one extra who was so enthusiastic in his laughter that it was throwing off my timing," recalled Gulman in an interview with Collider. "He was just laughing too loud, and right when I was about to say something to Todd about maybe getting the guy not to laugh so loud, I realized that it was Joaquin Phoenix. It’s my best Joker story. I can’t believe it took me six takes to figure out that the man with the really bizarre laugh was the Joker."
Upon seeing the finished film, Gulman loved it and Phoenix's performance, personally identifying with some of the professional frustrations Arthur went through. The movie has proved a hit with audiences as well, setting the record for highest-earning R-rated film of all time.
Directed by Todd Phillips, Joker stars Joaquin Phoenix, Robert De Niro, Zazie Beetz, Bill Camp, Frances Conroy, Brett Cullen, Glenn Fleshler, Douglas Hodge, Marc Maron, Josh Pais and Shea Whigham. The film is now in theaters.