Autobiographical Role: In the original one-man version of the show, Jonathan Larson essentially played a semi-autobiographical version of himself.
Cut Song: "Boho Days" was cut from the final version.
Reality Subtext: The musical reads as a love letter to Michael, who is The Heart of the show, and convinces Jon to stop being a selfish arrogant artist and focus on the people in his life. Matt O'Grady, Jonathan Larson's lifelong friend, served as the inspiration for Michael and revealed in an interview that Jon dedicated the show to him. Every time he sees a performance, it allows him to be with Jon again for a few hours and is flattered that Jon made him the emotional center of it.
The film
Accidentally-Correct Writing: The pool scenes were filmed at the Tony Dapolito Recreation Center in the West Village simply because the filmmakers felt it resembled the place described in "Swimming". During filming, they discovered it was the actual pool Jonathan frequented.
Approval of God: Julie Larson, Jonathan's sister, praised Garfield's performance, calling it "both very lovely and eerie at times."
Dawson Casting: Andrew Garfield was 37 playing Jonathan at when he's 29 about to turn 30 and in the 1992 portions when he's 32.
Deleted Scene: The original assembly cut ran 2 hours and 20 minutes, whereas the finished film (minus credits) runs 1 hour and 50 minutes due to Miranda's desire to tighten the pace. As a result, quite a lot of material was left on the cutting room floor.
The film originally opened with a scene where Jonathan is stressing out backstage at New York Theatre Workshop before the performance of Tick, Tick...Boom!. This footage is in the trailer, but it was mostly cut during editing because the filmmakers wanted the opening scene to introduce Larson instead of his anxieties.
"Green Green Dress" was filmed as a fully-choreographed number, but Miranda cut it when he realized it slowed the pace of the film. It has since been released online.
There is apparently a deleted scene featuring a character named "Simon," who was meant to be a cameo by Jordan Fisher but he was unable to appear (see below) so the role was played by Noah Robbins.
Lauren Marcus plays a character named "Donna" whom Word of God says is based on Larson's friend Victoria Leacock Hoffman. Leacock Hoffman was known for filming Larson with her own Betacam, footage of which appears in the end credits and is recreated in the film, with Donna often seen following Jonathan around with her camera. Donna is never named onscreen and only has a single line in "Boho Days", but nevertheless has a prominent presence in multiple scenes, suggesting the part was trimmed down in editing: Marcus posted on her Instagram a behind the scenes image of an unused shot focused on Donna handing out playbills at New York Theatre Workshop, and in another post heavily implied her role was cut down.
Some bloopers released by Netflix include a scene of Garfield goofing off while delivering a line where Jonathan complains about Rosa to Ira, only to admit he doesn't say this in a Fleabag-esque Aside Comment: such asides are common in the stage musical's script, suggesting the original cut of the film featured more of these. In the finished film, Jonathan only does this during the focus group meeting.
The stage version (or at least David Auburn's version) includes a subplot where Susan becomes jealous of Jonathan's close friendship with Karessa. This is gone from the film, but brief scenes of the two joking around implying a closer friendship plus behind the scenes footage showing Jonathan hanging out with Karessa during a break in rehearsal suggest this may have been a subplot that was cut in the edit.
Fake American: The English Andrew Garfield continues his long tradition of playing American characters.
Irony as She Is Cast: Within the film, Jonathan is a music genius while his best friend Michael is stated (by Michael himself) to be a mediocre actor and singer, which is part of why he moved into the business sector before the start of the story. Jon thinks that Michael is being modest and tells anyone who will listen that Michael is one of the best actors he's known. In real life, Jonathan's actor Andrew Garfield had no professional music training or experience before being cast in the role while Michael's actor, Robin de Jesús, is a Broadway musical theater veteran of many years.
Missing Trailer Scene: In the trailer, Michael asks Jon at their apartment whether he's acting out of love or fear, with Jon comically replying that he's acting out of fear 100%. In the movie proper, Michael asks this question at the diner Jon works at, and while Jon doesn't directly answer him there, he later tells Susan that he's acting out of love. Completely lacking context, Susan can only reply with a "What?"
No Stunt Double: For the swimming scenes, a body double was hired to be Jonathan whenever Andrew Garfield's face wasn't onscreen. However, Andrew's father was actually a swim instructor and it turned out that Andrew could swim better than the body double could, so he just did all the swimming scenes himself. Andrew's dad was originally going to be the man swimming slowly in front of Jonathan but it didn't quite work out.
Production Posse: A ton of Broadway talent shows up in the film (especially in "Sunday") but special attention should be paid to the Hamilton and In the Heights alumni.
Robin de Jesús, the original Broadway Sonny, is Michael.
Joshua Henry also appeared in Hamilton, although he joined the show after Lin had left.
Longtime Miranda collaborator Utkarsh Ambudkar cameos as one of the advertising focus group members. Other members of Freestyle Love Supreme also show up throughout the film (including beatboxer Shockwave as one of the doormen in "No More").
The voice of Susan's friend Deborah, who calls Jonathan about problems with the speakers for Susan's show, is provided by Vanessa Nadal. She is Lin-Manuel Miranda's wife in real life.
Lin-Manuel Miranda's father, Luis, cameos as the concierge behind the desk in "No More."
Real Life Writes the Plot: New scenes were added into the film after extensive research into Jonathan Larson's life.
Ira Weitzman became a supporting character in the film after several interviews with the real man.
The scene where Stephen Sondheim gives Jon feedback on his musical.
The songs "Boho Days", "Swimming" and "Play Game" don't feature in the original Auburn script, having been cut from the original 1990 performance by Jonathan Larson himself - but were restored in the film.
Throw It In!: Stephen Sondheim voicing himself leaving an answering machine message for Jonathan came about because he had asked to rewrite it after seeing the film (feeling he wouldn't say what was originally there). Bradley Whitford was unavailable to re-record it, so Stephen did it himself.
Jordan Fisher was meant to appear for a brief scene but the day of shooting ended up being the same as his wedding day. Ultimately, the scene was cut due to time.
Chip Zien and Joanna Gleason were supposed to cameo in the "Sunday" sequence, as a nod to Into the Woods, but they couldn't make it due to COVID-19 restrictions. This resulted in Lin-Manuel Miranda cameoing himself.
Anthony Rapp revealed that he was asked to cameo but couldn't make it, for similar reasons. Instead, the movie uses archival footage of him thanking Jonathan Larson and dedicating the opening night of Rent to him.
Likewise, there had been plans to include more locations from RENT, such as Tompkins Square Park and the Life Cafe in the East Village. But COVID restrictions had those scenes relocated to the diner.
. Every time he sees a performance, it allows him to be with Jon again for a few hours and is flattered that Jon made him the emotional center of it.