When Harold Hill, a traveling con man, arrives in River City, he convinces the locals to start a band by purchasing the uniforms and instruments from him. His intention is to flee as soon as he receives the money. Librarian Marian Paroo suspects Harold is a fraud but holds her tongue since her moody brother, Winthrop, is excited about the band. As Harold begins to develop feelings for Marian, he faces a difficult decision about skipping town. The story follows fast-talking traveling salesman, Harold Hill, as he cons the people of River City, Iowa, into buying instruments and uniforms for a boys' band he vows to organize. The catch? He doesn't know a trombone from a treble clef.