Donald Hardwick (Dick Powell) is a stuffed-shirt, classical music professor. His family and small-town music college that he works are of equal mindset. When Don visits his black-sheep aunt in New York in order to find a buyer for his Rhapsody he is exposed to her shocking swing music crowd. His life begins to make dramatic changes after drinking a "lemonade" that turns out to be a Hurricane.
Tommy McCoy and "Dude" Markey are both in love with Harlem singer/dancer Nita. Markey robs a jewelry store and turns the loot over to gang-boss Murray Howard. Later, Markey robs the safe, steals the jewelry, and, in order to get rid of his rival for Nita, frames the robbery on McCoy. The latter's big-brother thinks otherwise and, with Nita's help, sets out to prove it.
Edna's grandfather is a conductor of a small orchestra that gives concerts in the park every Sunday. Because of lack of audience the city officials want to cancel these concerts. To stop this from happening, Judy and Edna gather a crowd the following Sunday; and to keep its attention, they themselves perform with the orchestra. Edna sings an aria and Judy sings 'Americana'.
J. P. Courtney wants to update the music on the radio program he sponsors, but his wife, Agatha Courtney, is the final authority and addicted to the classics and won't allow him to replace Professor Bistell and his symphonic orchestra. Conspiring with his daughter Sue and her friends, Marvo the Great, the Andrews Sisters, Anne Payne and bandleader Woody Herman, they devise a sabotage plot that gets rid of Professor Bistell, and a new sound is soon heard on the program.
A young woman who is unable to pay her rent gets some unexpected help when the other tenants throw a last-minute rent party in her apartment. In the process, they all charm the landlady out of a year's rent. The entire story is told in song (swing music) and dance (Jitterbug, Lindy Hop etc.).
At the Dimsdale Hall Finishing School, Assistant Dean Emily Godsall declares that any student who associates herself with swing music will be severely punished. Complications develop when she finds out that her boyfriend, a chemistry professor at the school, is also a well-known swing bandleader.
A vaudeville act inherits an old, beat-up building and decides to try to turn it into a hip new nightclub. Frank Sinatra's first screen appearance.
A bandleader, desperate to get his band's instruments out of hock, promises the pawnshop clerk-an aspiring songwriter-that he'll let the band's female singer do the clerk's songs at a local club if he will let the band "borrow" their instruments at night. The clerk's girlfriend, however, thinks that the band singer is after more than her boyfriend's songs.
The daughter of a formerly wealthy man tries to get a job singing on a radio show, but gets involved in a feud and murder.
Young Cab Calloway's mother is concerned, because Cab spends his days listening to the radio, pretending to lead a miniature orchestra. A deacon passing by the apartment hears him singing and advises him go to his wife's gypsy tea room. As she reads the tea leaves, she sees situations which lead to Cab and his orchestra performing musical numbers.