Songwriter Judy Walker, down on her luck and behind on her rent, receives a letter from well-known lyricist Phil Hale, telling her that he is going on tour and will respond to the songs she submitted later. About to be evicted by her sympathetic but stern landlady, Mrs. Madigan, Judy uses some ink eraser and a little imagination to change Phil's letter to one of introduction. Judy takes the revised letter to Phil's apartment building and, after telling the manager, Eric Parker, that she is Phil's niece, moves into Phil's apartment. When the J. C. Boswell Advertising Agency calls soon after, asking for Phil's latest music, Judy pretends to be Phil's secretary and agrees to bring the music in the morning. She then signs Phil's name above her own on one of her compositions. As Judy is enjoying her new comforts, her next-door neighbor complains about her noise and thereby sparks a pounding, screaming "noise war." The next morning, Judy plays her music for J. C. and his client, cosmetics manufacturer Maggie Conway, who is known as the Duchess de Lovely, and the duchess loves it. J. C.'s long-suffering assistant, Clyde Lyons, suggests asking lyricist Bob McKay to collaborate, but J. C. is skeptical, as Bob lost his girl friend, radio singer Dorothy Day, to Phil and refuses to work with him. Clyde goes to Bob's apartment, where Bob is waging a noise war with his neighbor, who, unknown to him, is Judy. Bob agrees to collaborate on the song, after which Clyde calls on Judy and discovers that she is Bob's neighbor. Clyde tries to arrange it so that they do not meet the next day at the office, but Judy arrives early and goes to lunch with Bob. Back at the office, the duchess decides she wants Dorothy to sing on her show, even though she has sworn off singing Bob's songs. J. C.'s conductor, Luigi Fernando, takes Clyde to Dorothy's apartment, and after Clyde threatens to use another singer, Dorothy agrees to go to the duchess' party that evening and listen to the songs. At the party, Bob and Judy's songs go over big, but Judy becomes jealous when the duchess tells her that Bob and Dorothy used to be an item. Clyde interrupts as Bob tries to soothe Judy and sets the couple to fighting when he accidentally tells them that they are neighbors. Later, on the night of the broadcast, Phil comes home and finds out from Parker that Judy has been using his apartment. She eludes him on the way to the studio, but Phil follows her, only to land in hot water himself when Dorothy overhears him arguing with Clyde and assumes that Phil is having an affair with Judy. Phil is determined to put Judy in jail, and when Clyde tries to explain the situation to Bob, Bob also assumes that Phil and Judy are involved. The show begins, but when Judy and Bob sing, Bob realizes that he loves her and tells the audience that Phil graciously gave Judy her start. The audience's applause prevents Phil from telling the truth, and so he wishes Judy well and reunites with Dorothy. All ends well as Judy and Bob embrace, the duchess is pleased with the program, and J. C. gives Clyde a raise.