Macheath is the protagonist and hero of The Threepenny Opera. As the master criminal of London, he commits murders and robberies with aplomb. He is dissatisfied, though, with the small-time criminal life and aspires to middle-class legitimacy. At the opening of the play, he is two weeks away from moving all of his holdings into a bank and turning his gang over to the cops. Macheath does not kill and steal because he is acting out against society; he kills and steals because he is good at it. If he can make money more easily as an honest man, he will do it.
Macheath does not change during the course of the play. At the end he remains a ruthless criminal who cannot see beyond his own self-interest. He never expresses remorse for his crimes, nor does he consider whether he should have done something differently. He always narrowly focuses on his immediate desires and needs.
Macheath possesses many traditional heroic traits: he is sexually appealing, funny, charming, and physically powerful. Throughout the play other characters comment on his charisma. In his actions, though, Macheath is anything but heroic. He is a thief, a murderer, and an adulterer. By making Macheath such an appealing, yet monstrous, character, the question is raised of what makes a person a hero. In the end, Macheath is perhaps best described as an ironic hero.
Peachum is Macheath’s antagonist, the character who opposes the hero and sets the plot in motion. Self-interest motivates Peachum throughout The Threepenny Opera. His only concern is making a profit with his business. Throughout the play, Peachum does not change. He never sways from trying to keep what is his. However, when the queen frees Macheath at the end of the play, Peachum gives up and accepts defeat. This moment of defeat is the only instance in which Peachum experiences a change within himself.
Peachum is an ironic villain. Traditionally, the villain would pursue evil essentially for the sake of evil. He would be someone who does horrible things because he is innately bad. This kind of villain actually reinforces traditional moral positions by making the audience see how awful a person is without them. Peachum, however, is the play’s strongest advocate of traditional morality. He obeys the law, reads the Bible, and wants his daughter to respect her parents. Yet he reads the Bible and obeys the law only because he thinks these activities will aide his business, not because he desires to be a noble citizen. Peachum’s use of traditional morality to justify his cruelty is a powerful way to emphasize both the arbitrariness of values and hypocrisy of religion.
Polly is the only character who undergoes any significant change in the course of the play. When the plays opens, she is a young, naïve girl who has fallen in love. She is initially horrified by the criminality of her new husband, but gradually she accepts the circumstances of Macheath’s business and even agrees to lead the gang in his absence. By the time Macheath has escaped from jail, Polly has been coarsened enough to try to trick Lucy into revealing where Macheath is hiding.
Polly’s relationship with Macheath causes the change within her character. She initially experiences his world of depravity and criminality with horror. But Polly eventually accepts the brutality all around her and helps to make Macheath’s thieves accept her as their new boss after Macheath tells them he has to leave. At the jailhouse with Lucy, Polly exhibits a toughness that contrasts her perceived sweetness. This toughness belies the jealousy that lies beneath, and it displays a virtuous girl that has become cruel.
Polly is unwavering in her love for Macheath. She loves him at their wedding, when he flees and gets arrested at a whorehouse, and even after she learns that he has another woman. This love creates a strong conflict with the self-interest that motivates the plot of the play. Polly’s love especially conflicts with her parents’ self-interest, and she represents the possibility of something bigger than self-interest.