PHOTO BY NIKO TAVERNISE / WARNER BROS.

Joaquin Phoenix, iconoclastic and often infuriating performer that he is, loves playing the Joker. Why shouldn’t he? His 2019 portrayal of the ubiquitous villain won him an Oscar. Reportedly, he was captivated by the idea of taking the tormented clown onstage for a singing-and-dancing revue; a Broadway show was contemplated.

The economics of film, though, are simpler than those of musical theater. Moreover, director Todd Phillips, a nihilistic journeyman who has repeatedly failed upward, wanted to once again step up to the DC Comics ATM. So, after snagging no less a talent than multihyphenate star Lady Gaga, a sequel — “Joker: Folie à Deux” — was born.

But here’s the unexpected twist: It’s captivating. It might even be somewhat unique. That’s a verboten word in most journalistic circles — there’s nothing new under the sun, and that’s doubly true in the world of film. But there are certainly things in “Folie à Deux” that I’ve never seen before. While it has its flaws, it’s unexpected and entertaining.

That alone makes it better than its predecessor.

We reconnect with Arthur Fleck (Phoenix), the self-styled comedian and part-time cackling cult leader, in a particularly dark and desperate ward of Arkham Prison. He’s awaiting trial for the quintet of very visible murders he committed in the last film, and he has run out of jokes — until he encounters a fetching admirer, Harleen “Lee” Quinzel (Gaga), in a therapeutic music program.

She’s a fan. He’s smitten. He’s heading to a trial and possible execution, yes, but he’s got a new lease on life.

“Folie à Deux” is a musical, despite the protestations of a director who seems to resist being lumped in with such crowd-pleasing fare. Fleck and Quinzel sing standards to one another in breathy, broken voices, pain seeping through renditions of “Get Happy” and “When the Saints Go Marching In.” In fantasy sequences, they sing in full voice and ’70s-style wardrobes; these raucous bursts of pop pastiche are at once disconcerting and heartwarming.

The characters keep returning to the 1953 song “That’s Entertainment.” Undoubtedly, they’re right — though it may not be all that satisfying to comic-book fans. This is a far cry from the world of the Caped Crusader — or even the funhouse interpretations of Tim Burton.

There’s commentary here. “Folie à Deux” is not a neat metaphor for any particular leader (although those angry mobs do look a bit familiar); rather, the script (by Phillips and Scott Silver) reflects on the ways in which we constantly join cults of personality, desperate for a celebrity to make us feel a certain way about ourselves — and how we tend to revolt when that feeling goes away. It’s a study of ego and projection in an era of constantly constructed public personae, a sympathetic indictment of fandom and idolatry.

And through it all, Phoenix uses cigarette smoke like an Olympic gymnast’s ribbon, buoyed along by a tide of confusion and cheers. Like the original, it’s a somewhat bleak place to spend two hours; Phillips’ worldview is a sinister one, and that keeps “Folie à Deux” from soaring too high. But it’s shockingly relevant and occasionally transcendent.

Like many others, I raised an eyebrow when I heard about “Folie à Deux.” I guess the joke’s on me.

My Rating: 8/10

“Joker: Folie à Deux” is now playing in theaters.