Frederick Wiseman's magnificent film offers a portrait of suppleness and agility, not only of the dancers' bodies but also of the august institution of the title. La Danse allows for spectators' full immersion into the action within the walls of the Palais Garnier, the 19th-century, neo-Baroque opera house where the company rehearses and performs. Roughly two-thirds of La Danse is devoted to rehearsal and performance, shot in deeply satisfying long takes of gorgeous young men and women starting, stopping, listening, questioning, repeating, perfecting. The rest is behind the scenes. As Wiseman shows empty corridors, the cafeteria, sewing rooms, and the nightly cleanup of the 2,200-seat theater, the stealth star of La Danse emerges: Brigitte Lefèvre, the company's composed, elegant artistic director. Shown in a meeting discussing the finer distinctions between "benefactors" and "big benefactors," Lefèvre nimbly tackles the potential messiness — but absolute necessity — of crass commerce fueling high art. When not administrating, Lefèvre seems happiest as a maternal martinet.