Rick Martin is a young Midwestern orphan cared for by an indifferent elder sister, living in his own isolated world. He is first drawn to an inner-city mission for alcoholics and its piano-accompanied hymns. Seeking a more portable instrument, his eye catches a trumpet in the window of a pawn shop. He works as a pin setter in a bowling alley to save up enough money to buy it. Tutored by Black jazzman Art Hazzard (Juano Hernandez) Rick grows into an outstanding, intuitive jazz musician (played by Kirk Douglas). He lands a job playing for a large dance band, getting to know piano player Willy "Smoke" Willoughby (Hoagy Carmichael) and beautiful featured singer Jo Jordan (Doris Day). In spite of being ordered to stick to the song arrangements, Rick prefers to improvise, and one night during a band break he leads an impromptu jam session, which gets him fired.