The Unfinished Dance

The Unfinished Dance is a 1947 drama film directed by Henry Koster and starring Margaret O'Brien and Cyd Charisse. It is set in a ballet company, and is a remake of the 1937 French film "Ballerina", based on a short story by Paul Morand. It won two awards at the 1948 Locarno International Film Festival.
Plot.
Aspiring ballerina Meg Merlin idolizes the head of her dance school, Ariane Bouchet, so much so that she often neglects her own studies just to watch Ariane dance. Only the intervention of kindly Mr. Paternos keeps her from being expelled.
When she hears that the "first lady of ballet," Lady Anna La Darina, is coming to the school, Meg is livid at Ariane being upstaged. She sets out to sabotage Anna's stay, beginning with mischief like turning off the lights in the middle of a session.
Meg is so obsessed in her quest, she even strikes dance student Phyllis Brigham when she dares prefer Anna's talent to Ariane's, earning a formal reprimand. During a performance of "Swan Lake," intending to switch off the lights again, Meg accidentally pulls the lever instead on a trap door. Anna plummets and seriously injures her spine.
Phyllis and friend Josie have a hunch who's responsible, so Meg is blackmailed by them. Worse yet, she discovers that Ariane is actually arrogantly self-involved, whereas Anna is generous and kind, coming back to the school to advise the students as best she can. When she learns the truth, Anna even forgives Meg, who now has a new idol.
Reception.
According to MGM records the film earned $1,129,000 in the US and Canada and $1,174,000 elsewhere but because of its high cost recorded a loss of $1,797,000. It was the first movie produced by Joe Pasternak at MGM to lose money.