In this musical extravaganza cousins in love blackmail their relative into financing their show even though he may lose a $10-million legacy by doing so.
Horace Hemingway (Guy Kibbee) is summoned to see his rich relative Ezra Ounce (Hugh Herbert), who tests Horace's purity and plans to give him ten million dollars and his actor nephew Jimmy Higgins (Dick Powell) nothing. Jimmy and his cousin Barbara Hemingway (Ruby Keeler) love each other, and he sings "When You Were a Smile on Your Mother's Lips and a Twinkle in Your Daddy's Eye." Ezra goes to visit Horace, and on the train Horace finds Mabel Anderson (Joan Blondell) in his bed. Jimmy calls on Horace to sell insurance and tries to sell Ezra his show; but Ezra has him thrown out and gets the hiccups. Barbara goes for medicine and meets Jimmy. On a boat he sings to her "I Only Have Eyes for You." Ezra hiccups and makes Horace's wife Mathilda Hemingway (Zasu Pitts) leave his bedroom. Horace calls drugstores until Barbara brings the elixir.
Ellsworthy (Berton Churchill) gives Jimmy a check for $5,000 for his show; but Mabel comes in and calls Ellsworthy a bandit for stranding her. Jimmy sings "Try to See It My Way" for Mabel, making Barbara jealous. Mabel tells Jimmy she can get the money from Horace. After Ezra's meeting of the Ounce Foundation for the Elevation of American Morals, Horace finds Mabel in his bed smoking. She asks Horace for $20,000 and starts to scream. Horace gives her a check. Mabel hides before Mathilda comes in. At a health restaurant Ezra tells Horace and Mathilda that they must stop Jimmy's show Sweet and Hot. At rehearsal Barbara tap dances and is hired. Horace tells Jimmy to stop the show but is carried out by chorus girls. Jimmy threatens Horace with blackmail and assures him that Barbara won't be in the show.
Sweet and Hot opens, and Jimmy asks Mabel to take Barbara's place. Ezra bring his alliance to see the show. Horace offers Jimmy $2 million to stop it, and Barbara arrives late. Bulger (Arthur Vinton) gives Ezra triple-strength elixir that is 79% alcohol. Mabel sings "The Girl at the Ironing Board." Jimmy sings "I Only Have Eyes for You" as he sells tickets and goes with Barbara on a train. In a dance fantasy they all look like Barbara. Ezra, Mathilda, and Horace drink the elixir and like the show. Men at a table argue what makes a show, and Jimmy sings "Dames." Dames in nightgowns get out of beds, bathe, and put on make-up before going to perform their dance. As Mabel and chorus girls sing, alliance men throw things and start a riot. Ezra and Horace are put in jail with the girls and tell Mathilda they want to stay. Jimmy and Barbara expect publicity and kiss.
As censorship closes in on Hollywood, this musical satirizes the influential puritans who try to stop licentious entertainment.