One night, Harlem, a young African American boy living in New York, wakes up to hear the sound of a trumpet player playing jazz music in the night. He tells his brother, Robby, about the musician, and soon Robby hears him as well. Both boys wonder whether the trumpet player might be Harlem's jazz guardian.

The next day, the boys' parents surprise them with a special trip. First, they're going to New Orleans for good food, family, history, and fun. Then they'll fly to Oakland, California, to visit the boys' grandfather and take in the sights and sounds of San Francisco. In both places, Harlem and Robby learn a lot about art, jazz, and Black history. And what's more, they keep seeing the trumpet player in various places, as if he is indeed a guardian angel. What lessons could the strange musician have to share?

In this children's story, two brothers on a trip with their family to discover their heritage and learn about Black history and jazz also encounter a mysterious trumpet player.