"Professor" Harold Hill arrives in small town River City, Iowa with a plan: to cheat the city residents out of money by convincing them they need a boy's marching band (to keep the kids out of trouble) and that he is the man to help them with this problem. He'll get the citizens to pay for uniforms and instruments, and then skip town with the cash, leaving the town and the band in the dust. He has his own problems, though: not only does he have no musical skill, he is also starting to fall head over heels in love with the town's librarian, Marian. Things go awry for Harold, but the end result is nothing he could have planned!