The film is biographical, telling the story of the life and artistic struggles of the French composer Hector Berlioz. Berlioz is shown as a recalcitrant medical student in an anatomy class dreaming of becoming a composer; at a demonstration during a performance at the Paris Opéra conducted by Habeneck; at supper with other young artists (Hugo, Janin, Dumas, Mérimée, Delacroix); and chasing after his future wife Harriet Smithson, after a performance of Hamlet. Also depicted are his life in a garret, while suffering from an illness due to an abscess in the throat; a visit from his mother who curses him; and the composition of the Symphonie fantastique. The film then shows his marital breakdown, the premiere of his opera Benvenuto Cellini, his travels throughout Europe, his second marriage to Marie Recio (called "Marie Martin" in the film), public acceptance in old age and reconciliation with his son.
Jean-Louis Barrault
Renée Saint-Cyr
Lise Delamare
Jules Berry
Bernard Blier
Gilbert Gil
Julien Bertheau
Catherine Fonteney
Louis Seigner
Noël Roquevert
Roland Armontel
Rivers Cadet
Fabienne Clery
Jacques Cossin
Lucien Coëdel
Jean Darcante
Joé Davray
Mona Dol
Maurice Dorléac
Jacques Dynam
René Fluet
Georges Gosset
Georges Lafon
Pierre Magnier
Georges Mauloy
Marcelle Monthil
Martial Rèbe
Louis Salou
Maurice Schutz
Roger Vincent
Michel Vitold
Georges Vitray
Eugène Yvernès