“Time is the thing,” says Lydia Tár (Cate Blanchett) in Todd Fields’ “Tár.”

Lydia, a world-renown conductor, is explaining her art as more than waving a baton around — not a mere “human metronome” — but rather an almost god-like ability to mold and contort time. The way Blanchett says this, with her arms swirling and shaping the air like clay, makes you believe, yes, she really can stop time.

But in “Tár” — a movie that likewise measures and sculpts moments with intense precision — time may be catching up with Lydia. She would seem impervious to downfall. Just after the opening credits roll, Lydia is there on a gleaming New York stage before a rapt audience being interviewed at length, and with almost oppressive accuracy for such fawning exchanges, by The New Yorker’s Adam Gopnik (as himself). Her listed accomplishments — conductor of the Berlin Philharmonic, protégée of Leonard Bernstein, a glass ceiling-shattering figure of the classical music world, an EGOT-winner with a new memoir, “Tár on “Tár,” out — are as impressive as her regal, polished stage presence.

Yet an introductory, fleeting moment of a phone camera pointed at an asleep Lydia, with mocking texts filling the screen, presages that the conductor’s rarified perch may be in jeopardy. “Tár,” which opens in theaters Friday, is situated in a very real high-art, big-media world. The spaces Lydia occupies are crisply contemporary architectures. The film is shot by Florian Hoffmeister with a cool, almost documentary-like perspective. It’s in these chilly, highbrow environs that Lydia operates with exquisite intellect and ruthless cunning — and Blanchett gives a colossal tour-de-force performance that may be the finest of her career, a career as decorated as Lydia’s.

“Tár,” written and directed by Fields, is, itself, distinguished by time. It’s Fields’ first film in 16 years, following the uneven 2006 misfire “Little Children” and his assured Oscar-nominated 2001 debut, “In the Bedroom.” At 2 hours and 38 minutes, you can almost feel him trying to make up for the lost years in “Tár.” Into it he funnels a gripping portrait of power and art, rigorous and devastating in its exactitude, while impressively less definite about a host of hot-button issues like so-called cancel culture, identity politics and #MeToo.

But though Lydia’s mounting issues — whispers about her propensity to groom young female players as her lovers; the suicide of a former trainee conductor following Lydia’s blacklisting of her; a young daughter (Mila Bogojevic) she leaves largely for her wife and philharmonic concertmaster (the brilliant Nina Hoss) to care for — are increasingly public, “Tár” is a thoroughly intimate film. We follow Lydia’s every move with a mix of awe (she is genuinely brilliant), curiosity (how much can she get away with?) and wonder. Just how deeply connected is Lydia’s cruelty to her genius?

The answers Fields supplies are not always satisfying, but for much of the film, he and Blanchett orchestrate a mesmerizing character study. The first such beguiling scene places Lydia, who describes herself off-handedly as “a U-Haul lesbian,” as a guest lecturer at Julliard with aspiring conductors. One describes himself as “a BIPOC pangender person” who is “not into Bach.” He shakes as Lydia, calmly tears into him as “a robot.” “Don’t be so eager to be offended,” she says.

Lydia’s perspective will rile some and be applauded by others, but in her smooth torrent of words she also makes less controversial, sincere arguments for “sublimating” and “obliterating” one’s self before art. Lydia spends much of “Tár” running her considerable business, manipulating the inner-workings of the philharmonic with her personal assistant (Noémie Merlant) and eyeing a young Russian cellist (Sophie Kauer). But when she’s rehearsing Mahler’s Fifth with the orchestra or in the full thrall of the music, Lydia is masterful. She may always be in some sense performing, but that doesn’t mean she isn’t being genuinely herself. “Music is movement,” Bernstein is heard saying in an old recording during the film. It’s clear that Lydia, too, is a force of headlong momentum.

And it can be devilish fun to see Lydia in motion. The way she diverts, like a shark with a new scent, across a school playground to buttonhole her daughter’s bully. “I’ll get you,” she threatens — and you know she means it. Or how she responds to seeing her daughter’s stuffed animals arranged like an orchestra, with each bearing a baton. “It’s not a democracy,” she sniffs.

Once the noise that’s plagued Lydia throughout the film finally consumes her, we don’t experience her downward spiral as you might expect. To her, it’s less Greek tragedy than a kind of pestering nuisance. “Tár” sags here and there from overwritten dialogue, and drama too drawn out. But I think its most glaring missteps comes in this chapter, when the movie’s sober spell breaks in a not-believable fit of violence and an off-key final note turns its protagonist into a punchline.

That I recoiled at these moments is a testament to the deft balance Fields strikes for much of the film’s running time, demurring judgement of Lydia and declining to saddle her with the expected art-vs-artist commentaries. But above all, it’s because Blanchett has created such a symphony of a character, one that uses every trick and tone of her vast repertoire, that any wrong note jars. The word I’m looking for is “maestro.”

“‘Tár,” a Focus Features release, is rated R by the Motion Picture Association of America for some language and brief nudity. Running time: 158 minutes. Three stars out of four.