“A great singer, chandeliers, champagne, and costumes—we see this at a distance,” Jean-François Sivadier says deep into Becoming Traviata, a spare and ravishing doc that positions viewers in the rehearsal room in the weeks leading up to his minimalist production of Verdi’s La Traviata. Sivadier is encouraging his star, Natalie Dessay, before a gutsy, scraping-out-the-soul performance of “È Strano” on a stage stripped of the usual operatic extravagance. His vision—shared by the film’s director, Philippe Béziat—is of that distance obliterated, of arias and singers and feelings laid bare. Dessay, as much a trouper as she is a brilliant vocalist, puts her head in her hands and then digs deep, pulling from herself a bruised and gorgeous lament, each note—each tortured misterioso—a raw and gleaming pearl. The film celebrates the sweat and prep that goes into such performances, showing us the rich collaborative interplay between the director and the star, who for most of the film is dressed for the gym and accompanied only by duet partners and rehearsal piano. Time with Dessay is worth treasuring, even when she’s not singing. “The music is almost orgasmic,” Sivadier enthuses. “For everyone but the girl singing it,” Dessay says back, bringing the house down all over again. The film is strongly focused, covering little but their work and her singing; Béziat understands that anything else would be a distraction.