In Seattle, Washington, brothers Frank and Jack Baker perform as the piano-playing duo, “The Fabulous Baker Boys,” at various hotel lounges and bars. One night, after a poorly received show at a tiki lounge, Frank and Jack are paid off by Charlie, the manager, who cancels their second performance and suggests they are out of fashion. On the drive home, Jack comments that they have not been paid off in fifteen years of working together, and Frank suggests it is time to take on a singer. The men audition thirty-seven women to no avail. However, a beautiful woman named Susie Diamond arrives an hour and a half late, and although Frank wants to disqualify her based on her tardiness, she has a hunch about the audition and insists on being heard. When Frank asks about her singing experience, Susie admits she is an escort and has none. Nevertheless, she impresses them with a passionate rendition of “More Than You Know.” Later, Frank paces nervously before a show at the Ambassador Lounge, angry that Susie is late for her first performance. She arrives in a sparkly dress, and Frank disapproves, so the brothers take her to buy something more understated. The performance starts off awkwardly, but Susie recovers and charms the audience, especially the men. After the show, Frank reprimands her for using a curse word onstage and takes a personal tip she was given, saying he will apply it toward the cost of the dress. Incensed, Susie demands that her name and face be added to the Fabulous Baker Boys poster. By Christmas, Susie’s presence has significantly boosted the Baker Boys’ popularity. She tells Frank and Jack that a waitress friend is making three times more at the Hilton lounge when they play there and suggests they request a percentage of the bar’s profits. Frank dismisses the idea, but Jack agrees and asks if she wants to get coffee after Frank has gone home. Susie declines, remarking that it would be creepy if she and Jack became romantically involved. Lonely, Jack goes to retrieve his dog at a veterinary hospital and returns home to find Nina, a young neighbor neglected by her single mother, watching television in his living room. The next week, Frank, Jack, and Susie leave town to play several nights of shows at an opulent hotel where they share a suite. Celebrating a successful show, Frank boasts to Susie about Jack’s intelligence. He also credits his brother for his marriage and two children because Jack taught him the box step before a high school dance he attended with his future wife. When Frank retires for the evening, Susie and Jack dance, but he retreats to bed after she claims she has had too much to drink. The next day, she finds Jack playing piano alone and Frank observes from afar as Susie admires his brother’s playing. Later, Frank admonishes Jack for his excessive cigarette smoking, then warns him to leave Susie alone. Learning that his son was injured, Frank returns to Seattle, leaving Jack and Susie to perform without him on New Year’s Eve. At the show, Susie sings “Makin’ Whoopee” while sprawled across the top of Jack’s piano, then leads the New Year’s countdown and kisses Jack at midnight. After the ballroom has emptied out, Susie drinks champagne and confides to Jack about her work as an escort, then complains that her neck is aching. Jack gives her a massage and makes love to her onstage. In the morning, Susie is offended when she finds him getting dressed by her bed. Back in Seattle, tensions arise between Susie and Frank, and Jack urges his brother to ease up on her. Susie goes to Jack’s apartment and finds Nina, who directs her to the jazz club where he is playing that night. There, Susie spies Jack passionately playing piano in a jazz trio. Sneaking back to his apartment, she greets him there when he returns and they make love. In the morning, Susie tells Jack she is thinking about leaving the act to sing commercial jingles. To her surprise, he supports the decision and comments that she will not be hard to replace. After their next gig, Susie tells Jack she will not return for another show and accuses him of being cold. Jack tells her she doesn’t know him, but she reveals that she saw him play at the jazz club and accuses him of living a lie by remaining in the Fabulous Baker Boys. Later, Jack and Frank play an ill-received show at the Starfire Lounge, and Jack berates Frank for booking an unpaid performance on an obscure telethon benefitting a high school gymnasium. On the broadcast, the brothers’ performance is interrupted by the emcee, prompting Jack to attack him. Outside, Frank accuses his brother of being unprofessional, while Jack counters that Frank has no dignity. Insisting he must maintain a professional demeanor for his family, Frank says Jack drinks too much, and the brothers tussle. Later that night, Jack passes out at a diner. He briefly considers seducing the waitress, one of the singers who auditioned for his act, but thinks twice after spotting Susie’s headshot on the wall. Arriving home, he finds Nina in his apartment yet again and reprimands her for treating him like a de facto babysitter. Shortly after, however, he apologizes and promises the girl another piano lesson. When Jack is offered a regular gig at the jazz club, he goes to Frank’s house in the suburbs and announces that he must quit the Fabulous Baker Boys. Seeming unsurprised, Frank says he will become a piano teacher. The brothers share a drink and cheer up as they play a song together. Later, Jack approaches Susie outside her apartment to apologize. Assuming he has come to ask her back, she expresses satisfaction with her commercial singing gig. She starts to go, and Jack asks if he will see her again. When she asks what he thinks, Jack says his intuition tells him they will reunite.