madrigal singers, musicians, guests, dancers, hunters, monks, servants and maids
3 Baritones, 2 Mezzo sopranos, 3 Tenors, 3 Sopranos, 3 Basses, silent role
The action takes place in the city and kingdom of Naples from 1586 to 1590.
To comply with the wishes of his family council, Carlo Gesualdo, Prince of Venosa, marries his cousin Maria d'Avalos, a young, lively woman who has already survived two husbands. Carlo, 'the melancholy dreamer,' is a lutenist and composer whose life is devoted to music; his only other pleasures are hunting and building his castle in Gesualdo.
The Viceroy of Naples, Don Garcia de Toledo, holds a spring festival, at which Maria falls in love with the brother of her first husband, the Duke of Andria, Fabrizio Caraffa; however, he too is married, to Donna Maddalena, Princess of Stigliano.
The sudden passion between the two is discovered. In the face of public opinion, Don Carlo believes his only course of action is to restore the honor of his house. He tries to avoid making a decision by provoking a hunting accident.
Maria and Fabrizio have received a warning. The only form of communication left open to them is letters. To save Maria's life, Fabrizio begs her to leave him. However, she insists on admitting her love openly and asks him to come to her. Don Carlo vainly seeks comfort in his music.
In San Severo Palace, Donna Maria awaits her lover. After pretending to leave to go hunting, Don Carlo now lies in wait for his victims in the house. The lovers meet one last time. They desire death, a wish granted them by Gesualdo's hired killers. Horrified, Silvana, Donna Maria's maid, flees with the child of her murdered mistress in her arms.
Donna Maddalena Caraffa dresses in mourning. The following morning, the cardinal and the viceroy learn of the terrible deed. Innocent people with knowledge of the circumstances are forced to make a confession. But the prince has left Naples and sought refuge in his castle Gesualdo. Donna Sveva d'Avalos laments the loss of her daughter.
Don Carlo does penance in Gesualdo. He has those who assisted in the crime flog him, while the monks sing a 'De profundis' in the chapel. However, the child's incessant crying allows the despairing prince no peace. He believes he can see a likeness between his child and his rival, Fabrizio Caraffa. He refuses to believe Silvana's assurances that the child is his, and silences it by swinging it to death.