Pope Clement VII wants to be known as a generous art benefactor and collector. The prelate has commissioned Benvenuto Cellini, a hot blooded but brilliant Florentine sculptor and goldsmith, to create a statue of Perseus killing the Medusa. The Pope’s treasurer, Balducci, mistrusts Cellini, preferring a local (and mediocre) sculptor, Fieramosca, to whom he has promised his beautiful daughter, Teresa, who in turn is in love with Cellini.
It is carnival time. Teresa watches the masked revellers from her window and hopes to catch a glimpse of her lover, Cellini. Though Balducci is suspicious, he hurries off to see the Pope. He feels threatened by the rebellious “bandit of genius” Cellini and intends to persuade the Pope to support the safe and submissive Fieramosca instead of him.
Teresa is a dutiful daughter and is concerned to discover Cellini in the house. Between fear and hope, the two sing of their love for each other and their disdain for Fieramosca, little realizing that the latter has also stolen into the house and is eavesdropping on them. Cellini reveals his plan to elope with Teresa to Florence: Balducci is to attend the theatre and while he watches the play, Cellini and his apprentice Ascanio, disguised as monks, will abduct Teresa. The spying Fieramosca overhears and vows to thwart them.
When Balducci returns unexpectedly Cellini escapes but Fieramosca is discovered hiding in the house. Balducci refuses to hear any excuses and calls the neighbours and servants to punish the intruder.
At the inn, Cellini’s friends and fellow metalworkers drink to the glory of their “divine art” until the Innkeeper comes to settle the tab. Just in time, Ascanio arrives with Cellini’s commission for the bronze statue of Perseus which must be cast the next day. Thanks to Balducci the funding is much smaller than expected. Infuriated, Cellini instructs the actors to mock Balducci in the commedia he will soon be attending.
Fieramosca vows to reveal to Balducci Cellini’s plan to elope with Teresa, but his friend Pompeo advises him to steal the plan instead. They will disguise themselves as monks and abduct the girl.
Balducci and his daughter arrive at the Carnival, where the play will be presented. The players exhort the Roman spectators to watch their commedia, which, at Cellini’s instigation, pokes fun at the Papal treasurer. Balducci watches angrily, and finally attacks the players who are mocking him. In the hubbub both sets of false monks fall upon Teresa, then upon each other. Cellini stabs Pompeo and is arrested. Just when all appears lost, a cannon is fired from the Castel Sant’Angelo, signalling curfew and the end of Mardi Gras. All candles and lights are extinguished, and in the darkness and confusion Cellini escapes and Fieramosca is mistakenly arrested and accused of murder.
Early the next morning Teresa and Ascanio look for Cellini in his atelier, hoping in vain to find him hiding there. Hearing the chant of monks in procession, they pray for Cellini’s safe return. Cellini enters and recounts his tormented night and miraculous escape. Teresa and Cellini vow never to be parted and to flee together to Florence. Ascanio tries in vain to remind Cellini of his duty to cast the statue of Perseus. “To hell with the statue!” says the sculptor. The lovers sing of the happiness that awaits them, but their flight is prevented by Balducci, who bursts in with Fieramosca, ordering him to take his “wife” home. At this point the Pope unexpectedly appears. His mind is on the statue, and finding out it is not ready yet, furiously decides to let somebody else cast it. Cellini is outraged: he would rather die than let another finish his work. He grabs a hammer and threatens to destroy the model of the statue if the Pope does not grant his wishes. The Pope, who cares more about his statue than anything, gives in and grants Cellini an unconditional pardon, as well as Teresa’s hand and time to cast Perseus. But on one condition: the statue must completed by the evening of that day, or else Cellini will be hanged.
Cellini has set up an immense foundry. The tension is at its peak. To fight his fears, Ascanio laughs and sings. But there is not much time for daydreaming. Cellini rallies his workmen to prepare bronze for the casting. Accompanied by swordsmen, Fieramosca enters, demanding satisfaction from Cellini and provoking him to a duel outside.
Cellini leaves; he feels the eyes of Rome upon him and wishes he could live the simple life of a shepherd, free from the worries and pressure that an artist has to go through to please his benefactors.
Meanwhile, Fieramosca plans to take advantage of the sculptor’s absence to bribe the workers against their master. The moment is favourable because the workers, dissatisfied with their low wages, just went on strike. But Teresa turns the plan to Cellini’s advantage and the workers turn on Fieramosca, thinking that he killed their master. To their surprise, Cellini returns and orders the workmen to dress Fieramosca in an apron and put him to work. Fieramosca happily submits to this punishment.
The Pope and Balducci come to watch the casting; both are sceptical about the success. The workmen exclaim in desperation that this is not enough metal to complete the job. In a moment of inspiration, Cellini orders his apprentices to throw all his previous metal works into the furnace in order to save the casting. The overloaded crucible explodes. For a moment, it seems all is lost. Then the bronze begins to flow.
The casting is successful. Balducci suddenly changes his mind and willingly hands Teresa to Cellini, and the Pope pardons Cellini. Art has triumphed and everyone sings its praise.
Synopsis reprinted by kind permission of the Metropolitan Opera, New York, revised by MCO.