Fact1: New local crime boss Fran McCarg wants percentage of band 's meager earnings, Fact2: Kelly save Firestone by sending him out, Fact3: clarinetist and long-time friend returns to find Tired and frustrated by drummer 's murder and subsequent departure of Al, Fact4: Al drops in to see Kelly, Fact5: feeling left out by Kelly ’s dedication to music
Output: Jazz cornetist Pete Kelly Webb and his Big Seven are the house band at the 17 Club, a speakeasy in Kansas City in 1927 during Prohibition. New local crime boss Fran McCarg Edmond OBrien wants a percentage of the bands meager earnings. When the band is opposed, Kelly decides to decline and see what happens. However, before the night ends, Rudy, the manager of the club, orders Kelly and the band to go to the house of wealthy Ivy Conrad Janet Leigh, a woman with a reputation for hosting rowdy parties and who has designs on Kelly. Reluctantly, Kelly arrives at the party and leaves a message for McCarg to call him there. When the call comes through, it is intercepted by Kelly’s drunk, hottempered drummer, Joey Firestone Martin Milner, who turns McCarg down. Kelly and his band are run off the road as they drive back to Kansas City. The following night, Firestone roughs up Guy Bettenhauser, McCargs righthand man. Kelly desperately tries to patch things up, but to no avail. As the band finishes its last number, two gunmen burst through the front door of the club. Kelly tries to save Firestone by sending him out the back, but Firestone is shot to death in the alleyway. Tired and frustrated by his drummers murder, and the subsequent departure of Al Lee Marvin, his clarinetist and longtime friend, Kelly, returns to his apartment to find Ivy waiting for him. Although he initially resists her advances, the two strike up a relationship that turns into an engagement. Later, all the local band leaders meet secretly to decide how to respond to McCargs pressure. When Kelly tells them he will put up no resistance, the rest go along as well. Detective George Tennel Andy Devine, who is trying to take McCarg down, tries to enlist Kellys help but is refused. McCarg tries to befriend Kelly, telling him that Bettenhauser acted alone in Firestone’s murder. He also presents Kelly with a new band member: his moll Rose Hopkins Peggy Lee. Rose, celebrating Pete and Ivys engagement, has a little too much to drink, and, due to an inattentive crowd, cannot bring herself to sing. An enraged McCarg chases her to her dressing room and beats her senseless. Kelly then turns to Tennel, who informs him that Bettenhauser has skipped town. Al drops in to see Kelly. The two come to blows over Kellys handling of the situation, but patch things up, and Al rejoins the band. Realizing he handled the situation wrong, Kelly tries to buy his way out but McCarg intimidates him into continuing. Meanwhile, Ivy, feeling left out by Kelly’s dedication to his music, decides to go her own way. Kelly gets a message to meet someone who turns out to be Bettenhauser. He tells Kelly that it was McCarg who ordered Firestones death, but if Kelly can come up with 1,200 by daybreak, Bettenhauser will help him get McCarg. Kelly agrees. Bettenhauser tells him he can find cancelled checks and papers in McCarg’s office at the Everglade Ballroom. Back at the club, Kelly arms himself, but is stopped by Ivy, who wants a last dance with him. He insists he does not have the time. Kelly finds the papers he needs, but before he can get out, a loud orchestrion begins playing; Ivy had followed Kelly to the ballroom, started the music and turned all the lights on. Kelly fearfully agrees to a last dance, but soon finds himself surrounded by McCarg and two of his men, one of them being Bettenhauser; Kelly has been set up. A shootout ensues. Bettenhauser climbs up into the ceiling to get a better shot, but Kelly shoots him first. McCargs other man tries to shoot Kelly, but Kelly throws a chair at him, causing him to hit and mortally wound McCarg instead. Seeing this, the gunman gives up. Back at the 17 Club, it is business as usual  the band playing, Ivy and Pete back together again, and Rudy still cutting corners wherever he can.