Marty 'Fats' Murdock is a slot machine mobster who wants his blonde girlfriend Jerri Jordan to become a singing star, even though her talent is doubtful. He hires an alcoholic press agent Tom Miller to promote Jordan, not only because of his past success with Julie London but also because he never crosses his female clients romantically. Miller launches a campaign that takes Jordan from club to nightclub, highlighting her presence and drawing attention from club owners and record bosses alike.
As Miller builds the buzz, he occasionally slips into fantasies about the legendary Julie London gracing the stage, only for the daydream to shift and leave him imagining Jerri in that spotlight instead. Miller’s work stirs real interest and soon offers begin to surface, but not all observers are convinced that Jordan truly has the goods to sustain a show-business career.
Murdock, meanwhile, is blunt about his true wishes: he believes Jordan’s true dream is something more domestic, and he tries to dissuade Murdock from pushing her toward a professional singing path. Nevertheless, Murdock insists on recording a song he composed while in prison, "Rock Around the Rock Pile," a playful parody of a famous rock anthem. Jordan lends her voice to the part of a prison siren for this track, and Miller heads to Chicago to pitch the record to Wheeler, a former mob rival who now controls the jukebox market.
Wheeler is intrigued by the tune and by Jordan’s voice, and he initially contemplates signing both Jordan and the songwriter. But when Miller reveals that the songwriter is Murdock, Wheeler balks and refuses to promote the song. This setback only fuels Murdock’s campaign to dominate the business, and he begins pressuring bar owners to stock jukeboxes that carry his music. The tension escalates as Wheeler arranges a hit on Murdock to take place at the very rock show where Jordan is set to debut.
On the journey to the show, Murdock confesses to Mousie that he does not want to marry Jordan. Mousie—who secretly edits their phone conversations to remove romance—tells Murdock that their relationship is not personal but strictly business. Back in Chicago, Wheeler’s suspicions about the Miller-Jordan affair persist, but the immediate danger is the assassination plot that looms over the show.
Backstage, Jordan turns to Miller, admitting that she is in love with him and sharing a kiss. She also reveals a surprising truth: she is a talented singer who lied about pursuing a show business career because she didn’t want the public spotlight. With this confession, she steps onto the stage and performs a heartfelt number about her love for Miller. When Murdock arrives, Miller announces their love story and receives Murdock’s blessing.
The drama takes a sudden turn as Wheeler’s assassins open fire on Murdock. Miller fights them off and shoves Murdock onto the stage to perform his song, hoping the spectacle will deter the gunmen in front of a stunned audience. Wheeler arrives, impressed by the crowd’s response, and aborts the hit, ultimately offering Murdock a deal. The movie closes with Miller and Jordan sharing a kiss on their honeymoon while Murdock and Mousie perform on a television show in the background. In the epilogue, it’s revealed that Miller and Jordan have five children, and Murdock often acts as a babysitter.
