In 1930, in New York, popular vaudevillian Bill Miller announces at his wedding reception that he is going solo, stunning his partner, Ben Bailey, and his agent, Leo Lyman. Bill dismisses Ben's and Leo's warnings about the difficulties he will face and begins touring with with his bride, singer Mary Turner, at his side. When Bill proves a failure, Leo suggests he hire a stooge, or song plugger, to spice up his act. Bill contacts a music publisher, who recommends Ted Rogers, a bumbling employee he is anxious to get out from under foot. After picking up Ted, Bill shows up late for a rendezvous with Mary, who accuses her husband of putting his career before all else. In the taxi to the theater where Bill is performing, the newlyweds argue in front of a bewildered Ted, then Bill orders Ted to pay the cab fare. Assuming that Ted knows why he has been hired, Bill instructs the young man to take a box seat and begins his act. When Bill announces to the audience that the composer of the hit tune "For You" is in attendance and shines a spotlight on Ted, Ted is confused but gamely tries to sing. The orchestra keeps raising the pitch at Bill's request, however, and Ted's screechy, off-key voice provokes much laughter. Humiliated, Ted runs from the theater, to the disappointment of Genevieve "Frecklehead" Tait, the impressionable young woman sitting next to him. Bill is thrilled by the crowd's enthusiastic applause, as are Leo and Frank Darling, a booking agent, but panics when Frank states that he cannot book Bill without his stooge, whose name Bill does not even know. Bill finally tracks Ted to his mother's house and by offering a substantial pay raise, convinces him to join his act. Bill and Ted begin touring the vaudeville circuit, while Mary, who has quit show business at Bill's behest, stays at home. One night, Bill becomes so drunk that he cannot go on, and Ted is forced to perform without him. Ted is a hit, but refuses to consider agent Sam Heinz's suggestion that he could earn more money and recognition without Bill. Ted then covers for the still drunk Bill when Mary telephones their hotel. Later, Bill and Ted return to New York, where they are scheduled to play the Palace Theatre, the most prestigious venue in vaudeville, on Mary's birthday. At the train station, Ted presents Mary with songs lyrics he has written in her honor, entitled "A Girl Named Mary and a Boy Named Bill," and afterward, Mary beseeches Bill to acknowledge Ted publicly. Ted, meanwhile, is reunited with Frecklehead, who has been following his career and still adores him, and at Mary's birthday party, dances and flirts with her. Bill fails to show up for the party, and by the time he arrives home, having spent the evening negotiating a new contract with theatrical producer Sutherland, Mary is so upset that she locks him out of their bedroom. After Ted urges him to improvise a melody for "A Girl Named Mary," Bill sings through the door, and Mary's anger dissolves. Ted, Bill and Mary then go to a nightclub, and there Ted gets drunk and slaps Heinz after he calls Bill a "third rate ham." The next day, Bill drags a hungover Ted to Sutherland's office and cajoles him to sign the contract without reading it. Mary is disappointed to learn that Bill is not giving Ted billing as he had promised, while Frecklehead accuses Ted of allowing Bill to make a fool of him and refuses his engagement ring. That night, Ted appears anonymously with Bill and is the hit of the show, but Bill still refuses to acknowledge his contributions. Fed up with Bill's selfishness, Mary visits Leo at his office to express her frustrations, then hides when Bill shows up unexpectedly. When Bill starts to discuss the large advertisements he wants for his "solo" act, Leo becomes disgusted and tears up Bill's contract. Mary then emerges and tells Bill she is leaving him. Bill gets drunk that night and denounces Ted when he tries to counsel him about making up with Mary. Hurt, Ted declares he is leaving the act, and Bill goes on without him. Halfway through his dismal performance, however, Bill stops and apologizes to the audience. After Bill finally acknowledges Ted's contributions, Ted appears, yelling at him from the box seats. The two then sing one of their signature duets, while Mary, Frecklehead and Leo watch happily from the wings.
