The conductor Pierre Morhange recalls his youthful experiences in a boarding school for difficult-to-educate children, which he attended shortly after the end of the Second World War. His teacher Clément Mathieu sets himself apart from the other staff at the institution by not relying unilaterally on draconian punishments as an educational concept. As Mathieu actually wanted to work as a musician, he uses the boys' potential to form a choir.