The three "bums" in the Sunday brunch number are played by The Original Broadway Cast members from Rent: Adam Pascal, Daphne Rubin-Vega, and Wilson Jermaine Heredia. The other "patrons" are all Broadway legends. The cook at the diner is the director, Lin-Manuel Miranda.
Before deciding on Andrew Garfield for the lead role, but not knowing if he could sing, Lin-Manuel Miranda asked a mutual friend, massage therapist Gregg Miele, if Garfield could sing. Miele replied that Andrew had "the voice of an angel." After Miranda left, Miele called Garfield and asked if he could sing.
Despite having no singing experience, Andrew Garfield became Lin-Manuel Miranda's top choice to play Jonathan Larson after seeing Garfield's Tony-winning performance in the 2018 Broadway revival of Angels in America. Miranda said that he felt a connection between Garfield's performance as Prior Walter and Larson.
Scenes depicting Jonathan Larson performing the in-film version of "Tick, Tick... Boom!" were shot at the New York Theatre Workshop, during the time he performed it as a one-man show, in 1990, and where Larson's mega-hit musical "Rent" would later officially premier Off-Broadway in 1996.
Barbara Ames: Lin-Manuel Miranda's elementary school music teacher, giving Michael flowers after one of his plays. Miranda has said Miss Ames changed his life and led him toward a career in the arts.