While the original “Joker” pondered whether we could empathize with a villain, its sequel explores if we are prepared to see him experience love, face emotional struggles, and perform.

Again written and directed by Todd Phillips, “Joker: Folie à Deux” (★★½ out of four; rated R; hitting theaters Friday) aims for bolder moves than the audacious 2019 original, which was a best picture nominee and held the title for highest-grossing R-rated film until “Deadpool” and “Wolverine” joined forces. This time, Joaquin Phoenix’s troubled Joker finds companionship with Lady Gaga’s lively portrayal of Harley Quinn.

However, not all elements work seamlessly together, as the grim yet effective “Folie à Deux” tries to blend prison drama, courtroom thriller, and supervillain musical into one. With Gaga singing classic pop hits and Phoenix showcasing his tap-dancing skills, at least one of these elements certainly succeeds.

It has been two years since Arthur Fleck (Phoenix), a failed party clown and comedian, became something of a folk “hero” in Gotham City after committing five murders, including one on live television. His notoriety has been kept alive by TV and literature, but inside Arkham State Hospital, a gaunt and ashen Arthur struggles to maintain his infectious laughter. He’s now a shell of his former self, taking meds while a mocking prison guard, Jackie (Brendan Gleeson), presses him for jokes.

As Arthur’s highly anticipated trial approaches—where the state is seeking the death penalty—his lawyer (Catherine Keener) aims to present an insanity defense, claiming that it was the Joker persona responsible for the murders, not Arthur. Yet, his thoughts shift to romance: during a music therapy session at Arkham, he encounters Lee Quinzel, a troubled artist who has a notorious past and becomes a Joker admirer. She reveals that witnessing him kill live on air made her feel less alone.

Similar to the first film, Arthur has fantasies of fame and now imagines duets with Lee, singing classics like the Bee Gees’ “To Love Somebody.” They share a bond through music, reciting “Get Happy” lyrics softly to each other. Lee is later moved to a minimum-security ward to distance her from his “bad influence,” yet she plays an integral role in Arthur’s courtroom drama.

Phillips establishes a compelling storyline early on, juxtaposing the harsh realities of prison with Arthur’s newfound happiness. However, the momentum falters during the trial, as “Folie à Deux” becomes an unnecessary repetition of the first film, featuring returning characters and similar plot lines. It allows for a few genuine moments of regret from Arthur, and Phoenix oddly channels a Foghorn Leghorn-like demeanor when he defends himself.

The initial “Joker” was marked by a dark and toxic tone, albeit layered with psychological depth. This sequel retains a somber atmosphere, but at times it carries a sense of hope and warmth. This emerges from the palpable chemistry between Gaga and Phoenix during both tender moments and lively musical numbers as they perform songs from the Great American Songbook, including tracks like “The Joker” (the Anthony Newley version, not the Steve Miller Band). Fans of Batman comic lore are aware of the tumultuous relationship between Joker and Harley, and it’s entertaining to watch the evolution of Arthur and Lee’s tumultuous romance.

While “Folie à Deux” hints at a brighter, more whimsical quality, Phillips misses the opportunity to fully embrace the musical genre and create something truly unique. Instead, it merely grazes the surface, leaving viewers wishing for a deeper dive, especially with such talented performers involved.