Chicago bandleader Johnny Prentice continually loses bookings because of his bad temper. After his adopted son Half-Pint is temporarily taken away from him because he has no tutor, several bandmembers, including Tony Wonder, lose faith in Johnny and leave the band. Johnny hires lovely Linda Rogers to tutor Half-Pint, and in time, Johnny and Linda fall in love. She encourages Johnny to follow his dream of playing at the Cocoanut Grove club in Los Angeles, and tells him that the club auditions and showcases unknown bands every spring. When Dixie, a band member, wins a trailer through a cereal contest, Johnny sees his opportunity and buys an old jalopy to take the band to California. At a trailer park, Linda encourages Hula Harry, the pianist, to play his own songs, while she sings. Harry's song is a big hit at the camp, and Johnny discovers both Harry's and Linda's talents. In the midst of a downpour in Kansas, the car literally falls apart and is towed by garage owner Bibb Tucker. Bibb is a whiz with sound effects, so Johnny convinces him to join the band and tow them to California. After more adventures, they reach the club and audition, but club owner Robert Grayson mistakes Tony Wonder's band for Johnny's and hires them instead. Crushed by his apparent failure, Johnny and his musicians disband, and Linda, believing he is flirting with Hazel from Tony's band, boards a bus headed for Chicago. Backstage at the Grove, Bibb overhears Tony scheme to get Harry's signature song and realizes that Tony's band was hired by mistake. He tells Johnny, who, with the speakers on Bibb's truck, drives through Los Angeles asking his scattered band members to return to the club. Overhearing his announcement, the band members drop their jobs and rush to the Grove, where they beat up Tony's band and lock them in the dressing room. Meanwhile, Johnny catches up with Linda's bus. The band is a big success, and Johnny and Linda arrive just in time to play their signature song with Grayson's approval.