In France, in 1930, the supervisor of a reformatory for young offenders seeks to awaken in them the love of music by forming a choir, despite the skepticism of the institution's director.

"La Cage aux rossignols" (A Cage of Nightingales) is the title of an autobiographical book that a young writer try to publish, which would allow him to marry so charming Martine. Under a pseudonym, Clement's book is published in La Dépêche a daily newspaper that publishes novels as serials. Martine can read the novel to her mother (voice-over). Story of this music lover, supervisor of a boarding reserved for young offenders who asks only to discover the joys of music by forming a choir. But Clément does not have only friends. The director of the institution, man petty and narrow-minded, never misses an opportunity to throw a spanner in the works...—Sangria K, France