'Vox Lux' review: LI's Natalie Portman hits a high note in this dark fable

In Brady Corbet’s “Vox Lux,” a teenage girl named Celeste survives a school shooting, turns the tragedy into a hit song and then, years later, learns that her music has inspired another, similar crime. A journalist asks: How does Celeste — played as an unhinged adult by Natalie Portman — feel about that? In response, Celeste offers free concert tickets to terrorists. “I am the new faith,” she proclaims.

As biopics of fictional pop-stars go, “Vox Lux” is less about chasing your dreams than watching them curdle into something evil. (“Glitter,” this ain’t.) With a soundtrack of contemporary could-be hits by Sia, a thrillingly discordant score by cult hero Scott Walker and a wigged-out performance from Portman that recalls her Oscar-winning turn in “Black Swan,” “Vox Lux” is a dark fable about fame, image and entertainment that perfectly captures our culturally chaotic moment. It’s the art-house flip-side to “A Star Is Born.”

For the first half of “Vox Lux,” young Celeste is played by Raffey Cassidy as a mousy teen with a small singing voice. Her post-shooting ballad, however — played with her sister, Ellie (Stacy Martin), on keyboards — goes viral and attracts first a hard-driving manager (Jude Law, with stubble and an American accent) and then a record deal. “I don’t want people to think too hard,” Celeste says of her music. “I just want them to feel good.”

By the time Celeste is played by Portman, she has become an alcoholic, a mother (Cassidy returns, eerily, to play her own daughter, Albertine), a Kanye-caliber motormouth and an emotional wreck. Celeste’s preconcert meltdown in the bowels of an arena is a harrowing and grimly hilarious performance, reminiscent of Cassavetes-era Gena Rowlands. Once on stage, wrapped in a black catsuit and with cheeks covered in glass tears, Portman puts on a deliciously sinister show.

Corbet, whose previous film, “The Childhood of a Leader,” was also a biopic of sorts, has so much to say about the entertainment-industrial complex that he can’t clearly articulate all of it. What’s more, after connecting so many modern cultural dots — from terrorism to EDM — Corbet returns to a mythical tale as old as the blues. Still, “Vox Lux” is a heady experience, a canny pop critique set to an ominous beat.