Der Zarewitsch (1954)

Sonja, a little ballerina at the Grand Theater, is secretly in love with the handsome tenor Luis Mariano. One night, she hurts her feet while dancing and under the influence of a sedative falls asleep and starts dreaming. She is Sonja Ilyanova now, a young gypsy dancer who dreams of performing before Alexei, the son of the Czar.