Here’s a sequel we didn’t need.

It seemed like a nice idea to add Lady Gaga and music to the mix as Joaquin Phoenix returns to the role that rightfully won him his first Oscar as Arthur Fleck, a failed stand-up comic who finds infamy as Joker, the clown prince of crime , with matching clown makeup, whose followers cheered when he shot and killed an obnoxious TV talk show host (Robert De Niro) live on TV.

The music isn’t exactly a new idea, as in the 2019 origin story, Joker memorably swayed on a staircase during Gary Glitter’s “Rock and Roll Part 2,” twisting his face, body and dirty red lip gloss into physics-defying contortions. There was definitely an encore.

What we get, however, is a static, claustrophobic mood piece that follows Arthur in an insane asylum, where he has been placed to save society from his murderous, manic episodes. Director Todd Phillips re-teams with Scott Silver on a script that makes us wonder how much of the story is real or just the wild fantasies swirling in Arthur’s overcrowded mind.

Unlike the deservedly popular first film, which borrowed outrageously and constructively from two Martin Scorsese film classics, “Taxi Driver” and “King of Comedy,” the sequel frustratingly fumbles around for an original place to land. Unfortunately the search is futile.

Even sadder is that the sequel reduces Lady Gaga to a supporting role. “Folie a Deux” is a French expression meaning “madness for two”. We all know Gaga could have totally played off that concept of an idea. Instead, she’s been reduced to a Joker groupie, admiringly misty-eyed since watching a TV movie about his life. Even Jackie (the great Brendan Gleeson), a sadistic guard at the Arkham State Asylum, thinks Arthur is a celebrity.

Still, the terribly watchable Gaga – a true star in any medium – makes the most of her role as Lee Quinzel, a fellow inmate and convicted arsonist who introduces herself as Harley Quinn, Joker’s accomplice and lover from DC Comics. Why not? At least that fever dream gives her something to dig into and sing about (“If My Friends Could See Me Now”).

Otherwise, the film wastes a lot of time watching Arthur’s trial repeatedly. His lawyer (a criminally exhausted Catherine Keener) tries to use the insanity plea to save him from the death penalty. But Gotham City’s district attorney, Harvey Dent (Harry Lawtey), insists that Arthur is not a split personality, but a desperate loser eager to redeem himself.

The process is shockingly banal. It’s no wonder Phillips throws in music to break the monotony. The director says the pair’s duets on songs like “Get Happy” and “For Once in My Life” were recorded live to emphasize emotion rather than slick singing. The songs are meant to feel like the oldies that abused child Arthur listened to with his mother, whom he later murdered.

It’s a crushing letdown that, apart from the whispered song fragments, so little emotion comes across on screen, although the way Arthur and Lee dance in the rain in the pale moonlight is truly moving. It is a shared romantic illusion that actually defines folie à deux. And it’s over in a dreamy poof of what could have been.

Nothing about this sequel can match the theatrical flamboyance and bruising that characterized the first film. Phoenix still captures Arthur’s desire with a striking, wounded tenderness. And Gaga shows how her starshine really can’t be dimmed no matter how the movie tries.

Yet ‘Joker: Folie à Deux’ seems to punish itself for the unjustified criticism that the first film incites violence. There is very little mischief or madness this time around. Talk about sucking the life out of a party. Lee says to Arthur during an onstage fantasy sequence, “Come on, baby, let’s give the people what they want.” I’m still waiting.