A remake of the silent film, "Her Sister From Paris", Moulin Rouge stars Constance Bennett in a dual role as twin French entertainers.
One is married to a songwriter (Franchot Tone), who doesn't want his wife to return to the stage. In order to hide the fact that she's gotten a job in a musical, the married sister poses as her unmarried twin, while the twin pretends to be the married one.
The husband attends the musical and falls madly in love with the leading lady never suspecting that she's his own wife. The married woman continues the ruse as a test of her husband's fidelity, and on and on it goes.
Special Notes: Moulin Rouge was withdrawn from circulation in the early 1950s to avoid confusion with the more famous Toulouse Lautrec biopic of the same name. Look for Lucille Ball in the nightclub scenes.