Drama set in post-WW2 France. When failed musician Clement Mathieu arrives as the new supervisor at a boarding school for difficult boys, he finds a grey atmosphere of severity. The joyless headmaster Monsieur Rachin runs the institution with an iron fist and gets very little out of the pupils. Mathieu feels powerless to make his mark until he decides to set up a singing choir. Gradually, the lives of the boys are transformed by the magic of music.