Lydia Tár is one of the greatest living composer-conductors, and first female chief conductor of the Berlin Philharmonic. In an interview with Adam Gopnik at The New Yorker Festival, she promotes several new projects, including her upcoming live recording of Mahler’s 5th Symphony. She relies on Francesca, her attentive personal assistant, and Sharon, her sickly wife and concertmaster. Lydia has lunch with Eliot Kaplan, a conductor who also manages a fellowship program she founded for aspiring women conductors; and talks about replacing her assistant conductor, Sebastian, presumably with Francesca, and filling an open cello position in the orchestra.
Later, Lydia guest teaches at Juilliard. She ridicules Max, a student, for lacking interest in conducting the classical masters due to his identity politics, encouraging students to look past superficial differences to the music underneath. Max subsequently storms out.
In Berlin, Lydia receives Vita Sackville-West’s novel Challenge, sent by Krista Taylor, a former fellowship program member. Dream sequences and email interactions suggest Lydia groomed Krista into a sexually transactional relationship that later fell apart. Lydia blacklists Krista, ruining Krista’s chances for a conducting career.
Before a blind audition for a new orchestra cellist, Lydia sees one hopeful, the Russian Olga, in the bathroom. Attracted to Olga, Lydia secures her favors, such as changing her scorecard to ensure a spot in the orchestra, and a soloist position in the companion piece to Mahler’s 5th, Edward Elgar’s cello concerto. As she intensively prepares for a Mahler’s 5th recording, her relationships with Francesca and Sharon become strained, as both recognize her attraction to Olga.
Lydia informs Sebastian of his imminent replacement. Incensed, he indicates the orchestra is aware of her favoritism, and that it suggests abusive behavior towards young women. He speculates Francesca will be his replacement, implying an exchange of sexual favors. Unnerved by the accusations, Lydia plans to replace Sebastian with a different candidate.
Krista kills herself, leaving a note with serious allegations against Lydia. Lydia instructs Francesca to delete any emails from or about her. Lydia retains a lawyer as Krista’s parents plan to sue her. Lydia is haunted by screaming women in the distance, nightmares, chronic pain, an increasing sensitivity to sound, and enigmatic scribbles resembling those Krista once made. Her only respites are Olga, as well as her and Sharon’s adopted daughter, Petra.
While trying to write new compositions, she is continually disturbed and disgusted by her middle-class neighbor who cares for a dying mother. One day, after practicing Olga’s solo, Lydia follows Olga home to an abandoned, dilapidated apartment complex. Scared by a dog, Lydia trips and injures herself. She lies to Sharon and her orchestra, claiming the injuries were from an assault. Without telling Lydia, Francesca resigns upon learning she will not be replacing Sebastian.
An edited, out-of-context video of Lydia’s Juilliard class goes viral, and an article with accusations against her appears in the New York Post. Protesters meet Lydia as she returns to New York to promote her book and attend a deposition for Krista’s lawsuit. At the deposition, it is implied that Francesca has shared damning emails with the plaintiff. She takes Olga along, presumably with hopes of sex, but Olga abandons her. Back home, Sharon leaves with Petra, furious with the allegations, but more so at Lydia’s lack of communication or seeking her counsel as her spouse.
Lydia is removed as conductor. She sneaks into the live recording performance of Mahler’s 5th and, as the music begins, rushes onstage and attacks her replacement, Eliot. Advised to lie low by her management agency, she returns to her lower-class childhood home on Staten Island, where it is revealed that her birth name is Linda Tarr. She watches a tape of her mentor Leonard Bernstein’s first episode of Young People’s Concerts, “What Does Music Mean”. Her brother comes home and scolds her.
Sometime later, Lydia finds work conducting an orchestra in Southeast Asia. At a massage parlor/brothel, she picks her masseuse from a glass bowl. The escorts are staged and framed like her orchestra. One girl looks up into Lydia’s eyes, her position the same as Olga’s, and Lydia rushes outside to vomit. Lydia conducts her new orchestra in the score for the video game series Monster Hunter in front of an audience of cosplayers.