Fan secretly shoots Joaquin Phoenix filming staircase dance scene for Joker.

A fan secretly captured Joaquin Phoenix filming the now-iconic dance sequence for the movie Joker. The video has been shared online, much to the delight of fans.

The short video appears to have been taken from inside one of the apartments overlooking the staircase, situated in New York’s Bronx borough. Although there doesn’t seem to be any music being played on the set, the audio instead is from the apartment itself. The video shows Phoenix grooving silently with a cigarette in his mouth, in full Joker costume.

Someone saw the scene from #Joker go down in real-time. 🤯

🎥 azar0v/reddit pic.twitter.com/JZPblqdIHi

— Complex (@Complex) November 14, 2019

In the film, Phoenix dances down the steps -- with a backdrop of streetlights and classic New York fire escapes -- after transforming himself into the Batman villain. Many reviewers were outraged, however, that the song he danced to was by convicted pedophile Gary Glitter. The former glam rocker is in a British jail for sexually abusing three girls in the late 1970s.