It's very funny watching an old TV drama from the Eighties called "The Singing Detective" as it revolves around a mentally unwell man who can't tell the difference between reality and delusion, with his hallucinations taking the form of ridiculous musical numbers.
The whole time I was watching the show, it made me smile and think of the recent-ish box office bomb that was Joker 2 and how it probably should of taken notes on how to portray a genre-bending Musical. I can see it now, Harley Quinn is assigned to be Arthur Fleck's psychotherapist and tries to break down his Joker persona, but Arthur pulls a Hannibal Lector and gets into her mind instead, causing her to doubt everything she knows and even reality itself. She begins to seriously imagine herself as Joker's lover and partner-in-crime as they terrorise Gotham City with silly crimes. The audience themselves are left to question how much of anything is actually happening, beyond just the campy musical numbers which are clearly just Quinn's delusions. Then at the end of the film, Arthur performs the "killing joke" as it were and shoots Harley dead and reveals that it was all just a ploy to manipulate her into allowing him to escape as he leaves Arkham as the dark and gritty Heath Ledger-esque Joker as opposed to the wackier and sillier Joker in Quinn's fantasies.
Or something like that anyways. I feel like it would have gone down far better as you could honour both sides of the Joker's portrayals in a single film in order to try and please the varying demographics of people who like different interpretations of the Joker's character. Instead we got a sequel that seemingly hated the original film as well as the fans and wasn't made to entertain anyone but the director himself.