In July 1912, fast-talking traveling salesman “Professor” Harold Hill comes to River City, Iowa, a town hesitant of letting strangers in, especially ones trying to sell something. Harold calls himself a music professor, selling band instruments, uniforms, and the idea of starting a boy’s band with the local youth.
Harold decides he must “create” a situation of concern for the citizens in order for them to buy into his idea of starting a boy’s band, with himself as the leader. He convinces them that the arrival of the new pool table in town is “trouble,” and will only cause corruption of the city’s youth. The way to fight this, of course, is with music and a band.
Families begin to pay money to order instruments and uniforms, and, in return, Harold begins to teach the boys his revolutionary “Think System”: in order to learn the music, simply think about the melodies of the music in order to learn to play it.
Marian Paroo, the local librarian and part-time piano teacher, is not so easily convinced. She tracks down information to incriminate Harold and prove he is a fraud. She is ready to hand it over to the mayor, when she has a change of heart, seeing her younger brother come out of his shell by the arrival of his new instrument for the band.
Marian and Harold begin to see more of each other and their relationship develops. Then as the city is preparing to celebrate the Fourth of July, a rival and vengeful salesman, Charlie Cowell, arrives to expose Harold and convince the townspeople to arrest him.
Will Harold avoid trouble of his own? Will the boy’s band succeed? Do Harold and Marion end up making music of their own together? Enjoy this delightful piece of Americana that includes such memorable songs as "Ya Got Trouble," "Seventy-Six Trombones," "The Sadder-But-Wiser Girl," "Lida Rose," "Marian the Librarian," "Pick-a-Little," and "Til There Was You.”