Having just arrived in New York from the South, naïve classical composer and conductor Lowell Blackford shows up at a music publishing house and auditions his new "symphonietta" for both the company's manager and popular singer Ginger Gray. Lowell's audition is derailed by the arrival of "Waltzy" Malone, a boxing manager who is half-heartedly engaged to Ginger. No sooner does Waltzy announce to Ginger that he just sold a half-interest in his latest "discovery," a heavyweight boxer named "Killer" Kennedy, to nightclub owner Nick Sirocco, than Nick calls to tell Waltzy that Killer was knocked out during a warm-up bout. Distressed because Killer is scheduled to fight the world champion, Kid Mandell, Waltzy and Ginger leave for Killer's gymnasium. As they are rushing out, Ginger tells a befuddled Lowell that his florid music is "sweet." Lowell then realizes that Ginger mistakenly picked up his sheet music and asks the publisher's receptionist where Ginger is headed. When the receptionist refuses to divulge the information, Lowell reluctantly entrances her with a fixed stare and draws the address out of her. At the gymnasium, Lowell finds Waltzy and Dan Conlon, Kid's manager, whom Waltzy has learned was responsible for Killer's knock-out, brawling with each other. Seeing his music in Waltzy's coat pocket, Lowell stops the fight by paralyzing Waltzy with his stare and grabs his music just before Conlon knocks Waltzy out. After Waltzy regains consciousness, an apologetic Lowell explains that he inherited the Blackford "evil eye" and can entrance anyone with his stare. Waltzy soon concludes that Lowell's talent could be used to help Killer win his fight and orders Ginger to bring the composer back on a pretext. Believing that Waltzy and Nick are interested only in his music, Lowell agrees to showcase his symphonietta at Nick's club. The club's jazz band, with whom Ginger sings, has difficulty playing Lowell's staid orchestral piece, so Ginger writes lyrics for it and instructs the band to perform the music to a swing beat. Soon Lowell and his orchestra are the hit of the club circuit, and Lowell has fallen in love with Ginger. With Killer's big match approaching, Waltzy has Ginger "confess" to Lowell that Killer is her brother and that their grandmother is terrified that he will be hurt in the big bout. As hoped, Lowell offers to use his "evil eye" to entrance Kid during the bout. When the lovestruck Lowell later proposes to Ginger after a canteen benefit, however, Ginger, who is unsure about her feelings, stalls for time, and Lowell assumes she is not in love with him. Waltzy becomes frantic when he sees Lowell packing for home and tricks him into believing that Ginger has accepted his proposal. Waltzy's relief is shortlived, however, as Lowell then announces that he is planning to enlist. As a delay tactic, Waltzy hires the phony Dr. Clyde L. Star to examine Lowell and diagnose a heart condition that is treatable only by exposure to exciting activities such as boxing. When Ginger discovers Waltzy's latest ruse, she confesses the entire plot to Lowell, then angrily breaks with Waltzy. With the bout only minutes away, a desperate Waltzy tells Lowell that he will kill Ginger if he fails to mesmerize Kid. To save Ginger, Lowell jumps in a cab with Star, only to discover that Star is in cahoots with Conlon and he is being kidnapped by Conlon's thugs. Using his "evil eye," Lowell escapes and rushes to the boxing arena, where Killer is being torn apart by Kid. After a series of mishaps, Lowell finally manages to entrance Kid, who is then knocked out by Killer. Later, just before Lowell's last show at Nick's, Waltzy insists to the forgiving band leader that Ginger, who left New York during the fight, is still missing. As Lowell begins the show, however, Waltzy escorts Ginger to the stage and smiles as she and Lowell are reunited.