Oh... Rosalinda!! is a musical film directed by Michael Powell and Emeric Pressburger and released in 1955. It is based on Johann Strauss II's operetta Die Fledermaus.
The story is set in post-World War II Vienna and follows the glamorous Rosalinda (Ludmilla Tchérina) and her husband, the wealthy businessman Gabriel Eisenstein (Michael Redgrave). Despite being married, Gabriel has a wandering eye and is having an affair with the sultry chanteuse, Blondine (Anneliese Rothenberger).
Rosalinda discovers her husband's infidelity and decides to get revenge by attending a masked ball where Gabriel and Blondine are expected to be. She disguises herself as a Hungarian countess and seduces her own husband, who doesn't recognize her identity.
Meanwhile, Gabriel's friend, the philandering Dr. Falke (Anton Walbrook), also attends the ball with the intention of getting even with Gabriel for a past prank. He arranges for Gabriel to be publicly humiliated by revealing his affair to everyone at the ball.
The plot gets even more complicated when the prison governor, Frank (Anthony Quayle), who is a former suitor of Rosalinda's, shows up at the ball in his jailer's uniform and is mistaken for the Hungarian count who was meant to come with Rosalinda.
In the end, all the misunderstandings are cleared up, and Rosalinda and Gabriel are reconciled. The film features many musical numbers, including "The Laughing Song" and "Chacun à son goût."