A composer almost loses his girl-friend when she stars in his musical play in this adaptation of the operetta by Jerome Kern and Oscar Hammerstein.
"Play Us a Polka, Dot" is sung by Dot at a beer garden in 1898. Oscar Schmidt (Joseph Cawthorn) tells composer Sid Barnett (Donald Woods) to leave for bringing his daughter Adeline (Irene Dunne) home after 9. Dan Herzig (Ned Sparks) wants to do Sid's musical with Elysia (Wini Shaw), and Rupert Rockingham (Hugh Herbert) puts up the money. Major Day (Louis Calhern) recruits soldiers, and he asks Adeline to sing "Here Am I." On a farm Adeline sings "We Were So Young" to Sid, and he asks her to be in his play; but they quarrel. Rupert enjoys talking with Nellie Schmidt (Nydia Westman) and is not speaking with Elysia. Sid wants Elysia replaced, but Herzig says the money depends on her. At rehearsal Elysia sings "Why Was I Born?" but Sid gets Adeline to sing it better. Major Day offers to pay for the show with Adeline.
Rupert with a beard shows Sid a letter that he is secretly investigating Elysia. Adeline goes out with the Major on Sundays and tells Sid that he shouts at her every other day. At rehearsal a tenor sings "Mollie Donahue." Elysia hides a paper in her shoe and sends Rupert to the cobbler. Sid coaches Adeline on how to sing "Lonely Feet." The cobbler deciphers the message about forces sailing for Cuba. The Major invites the cast to a party. Nellie tells Rupert that she loves him. Elysia gives Sid drinks in her dressing-room. Oscar and others on the way to the party in horse-carriages sing "Twas Not So Long Ago." The Major orders champagne and dances with Adeline. Sid arrives with Elysia. The Major toasts Adeline and kisses her. Sid reprimands Adeline, hits the Major, and is thrown out. Rupert complains and is thrown out too. Adeline dines at the Major's home. He is not interested in marriage but invites her to move in. Adeline leaves and tells Herzig she is out of the show. Sid apologizes to Adeline and asks her to go on. She cries but agrees. Rupert finds a message in a shoe. Elysia gives Renaldo a knife, but he refuses to kill Adeline. Rupert arrests Elysia, but she says, "The show must go on." In big production numbers Adeline sings Lonely Feet" and "We Were So Young." Elysia cuts the rope of her swing, and Adeline falls. The show is closed, and Elysia is charged with attempted murder.
Sid and Rupert sing "Sweet Adeline," but Oscar throws beer on them. At the beer garden Oscar rips up Sid's new song. Adeline puts the pieces together and sings "Don't Ever Leave Me." Herzig tells Sid to kiss Adeline. She tells Oscar they are rehearsing, and Sid kisses her.
The Major symbolizes American imperialism as he wants to exploit but not marry Adeline. The musical Sid loves her and finally wins her.