The director Geremy Jasper begins his new musical in such a bombastic manner, complete with a mock-spaghetti western score, that it’s hard not to be at least intrigued. What is this cinematic U.F.O.?

We are, we quickly learn, in a postapocalyptic future in which a certain Plutonovich (Murray Bartlett, from “The White Lotus”) rules the airwaves and people’s minds with a reality competition beamed from his Onederworld lair in Satylite City — think “America’s Got Talent” at Thunderdome.

Despite the goofy names, these are scary times. A fresh-faced farm girl named O’Dessa Galloway (Sadie Sink, of “Stranger Things”) is informed that “It ain’t safe for a 19-year-old gal with stars in her eyes.” It’s actually even less safe for her parents, who are both summarily dispatched from the story within a few minutes. O’Dessa’s daddy (the singer Pokey LaFarge) was a rambler, so off she goes rambling as well, armed with his guitar. She ends up, naturally, in Satylite City, where she falls for the sweet Euri Dervish (Kelvin Harrison Jr.), a sex worker and cabaret singer whose funky-cool abode has a heart-shaped tub.

As he did for his previous film, “Patti Cake$” (2017), which was about an aspiring rapper in New Jersey, Jasper wrote the score with Jason Binnick. Their songs tend to be either emo Americana or power ballads; sometimes the first style builds into the second, as in “Yer Tha One.” And because O’Dessa has a mysterious prophecy to fulfill, she gets one song to rule them all, simply titled “The Song (Love Is All).” It’s worth noting that everyone sings well, sometimes surprisingly so. Sink, in particular, has an unforced elegance that carries even the by-the-numbers numbers.

While you might assume Plutonovich is the antagonist, he is overshadowed by the enforcer and pimp Neon Dion (Regina Hall, having a ball), whose severe bangs, dramatic outfits and even more dramatic expressions position her as a villain retrofitted from a 1980s music video.

That era actually feels like an aesthetic through-line in “O’Dessa,” and when watching the film my mind sometimes wandered to a pair of classic sci-fi turkeys from 1980: the Queen-scored “Flash Gordon” and the brain-melting musical “The Apple.” Which is a way of saying that “O’Dessa” might not be good by traditional standards, but it could well turn into a cult movie. There certainly are enough gasp-inducing scenes (what happens with Neon Dion’s electric brass knuckles is chef’s kiss), especially since, in many instances, you’re not sure what the director intended.

What is clearly deliberate is the single most interesting aspect of “O’Dessa” — the way Jasper reverses the usual roles. The traditional ramblin’ man is now a ramblin’ lass with a pompadour, while the prostitute with a heart of gold and a penchant for self-sacrifice is now a sensitive guy. Is a cliché turned on its head still a cliché? “O’Dessa” will keep you wondering, and that counts for something.

O’Dessa
Rated PG-13 for mild violence and language. Running time: 1 hour 46 minutes. Watch on Hulu.