Prelude
Two mimes, Comedy and Tragedy, open a trunk. Tonio, one of the members of an itinerant touring troupe, emerges. Tonio tells the audience that although they are seeing a play, they should remember that actors, even clowns, are real people who suffer and live lives of agony as well as joy.
Act I
The curtains rise on a village in Calabria where the town greets the arrival of the players: the leader Canio, his wife Nedda, and two other clowns, Tonio and Beppe. Canio invites everyone to the evening performance, and the villagers invite him to have a drink. One man jokes about Tonio having a chance to seduce Nedda. Canio, instantly serious, tells him that nothing relating to his wife is a joking matter.
When he leaves, the frightened Nedda worries that Canio might know something of her activities, but then she is entranced with the birds and sings of their freedom. Tonio listens to her song—consumed by desire, he begs her to love him. She treats him as the clown in their play. When she realizes that he is serious, she becomes angry, eventually striking him. He furiously leaves her just as her lover, a villager named Silvio, rushes in. Despite Silvio's passionate pleas, Nedda initially refuses to elope. Finally, she agrees to leave Canio.
Tonio, smarting from Nedda's rejection, returns and sees the lovers. He rushes off to fetch Canio. The two men arrive just in time for Canio to hear Nedda promise that she will meet her lover at midnight. Canio screams and chases the younger man who escapes. Tonio laughs at the furious Nedda; when Canio returns, she refuses to give him her lover's name. She leaves to prepare for the show. Beppe tells Canio that he must prepare to play Pagliaccio.
Thinking of Nedda's betrayal, Canio sings of his suffering— that he must play the clown although his heart is breaking.
Intermission
Act II
The villagers gather for the familiar comedy about Pagliaccio and Columbine, in which a man is betrayed by a faithless wife. A tryst between Columbine (played by Nedda) and her lover Harlequin (played by Beppe) is interrupted by Pagliaccio (Canio). As Harlequin escapes out the window, Canio hears Nedda make the same promise to meet Harlequin that she earlier spoke to Silvio. Forgetting he is onstage, Canio demands to know the name of Nedda's lover. She desperately tries to keep him in the play, but after two or three more moments, Canio explodes, telling Nedda that he is serious.
The audience applauds the realism of the acting. Nedda continues to defy Canio, finally crying that she will never tell him the name. Pushed beyond the breaking point, Canio stabs her. She calls for Silvio, who is too late to save her. Canio sees him and stabs him. The opera ends with the immortal line, "The comedy is over."