In 1906, the Congo Square Building in New Orleans, which was previously used as a slave market, is transformed into an African-American unemployment bureau. Close by there is also an African-American musical college, where little Reggie Tearbone, seven years old, is learning to play Bach on his cornet. He has trouble following the sheet and starts improvising. It begins to sound more like a jazz piece. Reggie's mother Ella works as a housekeeper for architect George Latimer. The Latimers are an old aristocratic family who has started to get financial problems. Because of this, when George's old friend Steve Porter come to visit, he offers the Latimer family, including George's daughter Kit and Ella, to return to Chicago with him. The whole family go to Chicago, but Reggie stays behind, having gotten a permanent spot in King Jeffers' Basin Street Band. Ten years later, Kit turns seventeen, and is left alone by both the Latimers and the Porters, who are out entertaining a client. Ragtime has developed from the regular jazz, and Kit meets the young street musician Johnny Schumacher when she is out walking alone. The two youngsters go to a party at a musical promoter together, and Kit plays the piano in a new style, leading to her arrest. She gets off by playing the boogie-woogie to the jury. Then comes World War I and changes everything, making the King Jeffers' Basin Street Band stop playing and Reggie, now known as "Rex Tearbone" and "King of the Cornet", goes to Chicago to continue his career. Steve's son Paul and Kit are now engaged to be married, but Paul is forced out in the war. Sadly he is killed in battle, and instead Johnny and Kit fall in love with each other and become sweethearts. When the war ends they marry. Johnny gets a job with a big jazz orchestra traveling Round, playing the cornet, but Kit doesn't want to join him on the road. Tired of not getting his place in the spotlight, Johnny soon quites the band and starts looking for true inspiration as a hobo. After a while, Johnny is contacted by the music promoter he once attended a party at, and is offered to come to New York. Kit has started working for the promoter, and they reunite in New York. Johnny gets to play in a new band and get a few good gig with the help of his promoter. After a slow start for the new band and its "innovative" sound, the audience realize that its great for dancing. The new sound is named "swing" and it revolutionizes jazz music completely.
