While playing in a bar in St. Louis, Jazz piano Jigger Pine meets aspiring clarinetist Nickie Haroyen who tries to convince him to put together a jazz band. After a drunk patron starts a fight, Nickie and Jigger are thrown in jail with Jigger's Drum kit and Double bass. They hear a prisoner singing a blues song and are inspired to set out for New Orleans where they hope to learn how to perfect an authentic bluesy sound. There they meet fast-talking trumpeter Leo and his wife Character who is a talented singer. Together, the quintet rides the rails, honing their technique in dive bars across the country.