On New Year’s Eve, Alfred, a tenor, sings to Rosalinde, his old lover and now married to Eisenstein, outside her window. Adele, Rosalinde and Eisenstein’s maid, is trying to plan to get the night off so that she may go to a ball with her sister, Ida. When Rosalinde enters, Adele pretends to have received a letter from her sick Aunt who needs help, but Rosalinde does not allow her to leave. Disappointed, Adele storms off. Alfred enters the home and loudly declares his love for Rosalinde, who denies him. However, Alfred finds her weakness and begins to sing again, which melts her. Their romance is short-lived, as they hear someone coming, forcing Alfred to leave, but not without her word that he may return to see her.
Eisenstein enters with his lawyer, Blind, having just come from court where Eisenstein was sentenced with eight nights in jail for hitting a police officer. Blind reminds him that he has to be brought to jail that night to begin his sentence, but is ushered out by the angry Eisenstein. Falke, Eisenstein’s friend, convinces him to go to jail in the morning so that he may attend Prince Orlofsky’s ball with him. Falke also instructs him to bring his pocket watch so that he can flirt with all the women at the party. Falke, playing both sides, invites Rosalinde to the ball, saying that she could possibly catch her husband in the act of flirting with other women. Rosalinde refuses, hoping to believe that her husband would be faithful, however Eisenstein bursts into the room lavishly dressed, which changes her mind. She and Adele give a faked sad farewell to Eisenstein as he “goes to prison,” however the three are comically thrilled with being able to continue with their own plans for the evening.
Once Eisenstein has left for the party with Falke, Alfred returns hoping to continue his rendezvous with Rosalinde. Again interrupted, Frank, the prison warden, enters and mistakes Alfred for Eisenstein. Rosalinde convinces him to play along, so Alfred is