The Threepenny Opera, written exactly two hundred years after John Gay’s The Beggar’s Opera (pr., pb. 1728), follows its model closely in plot and in the names of its characters. Like Brecht’s Berlin, Gay’s eighteenth century London underwent a period of expansion and consolidation, with a Whig government rotten with corruption. Gay’s opera chiefly satirizes the aristocracy’s manners and morals, although it also mocks marriage, politics, theatrical conventions, the prison system, and many professions. By providing the highwayman Macheath with the dash of a courtier, and whores with the grace of ladies, Gay indicts the vices of the upper class without needing to bring a single upper-class personage on stage.

Brecht adopts Gay’s ironic inversion of high and low life but aims, in place of the no-longer-vital aristocracy, at Germany’s triumphant, smug, powerful bourgeoisie. The criminal highwayman Macheath is called “Mac the Knife” (Mackie Messer), and while he is a thief, arsonist, rapist, and murderer, he also has the habits of a middle-class entrepreneur, keeping books, worshiping efficiency, and insisting on business discipline by his gang. His thieves are in competition with big business and the banks; they are defeated by the more predatory, shrewder, better-financed Jonathan Peachum. As he stands before the gallows, in what seems to be his farewell address, Mackie laments that he is a small fish about to be swallowed by a bigger one:Ladies and gentlemen. You see before you a declining representative of a declining social group. We lower-middle-class artisans who work with humble jemmies on small shopkeepers’ cash registers are being swallowed up by big corporations backed by the banks. What’s a jemmy compared with a stock certificate? What’s breaking into a bank compared with founding a bank?

In Brecht’s cynical, Marxist equation, the petty bourgeois equals the petty larcenist, while the tycoon finds his counterpart in Peachum, who licenses all the beggars in London and forces them to pay him 70 percent of their weekly take. Peachum transforms healthy men into deformed and pitiful creatures through the application of artificial limbs, eye patches, and the like—all carefully calculated to evoke the limited charitable impulses of the rich. Thus, if Mackie exemplifies the relationship between crime and business, Peachum highlights the relationship between the selfish capitalist ethic and the sacrificial morality of Christianity. Both Mackie and Peachum agree, in one of Brecht’s most famous statements, that eating comes first, then morality. Brecht suggests that Christianity and capitalism are really in the same ultimately corrupt league.

Brecht’s satiric attack on the bourgeoisie extends to its conventions of marriage, romantic love, and male camaraderie. Mac the Knife’s wedding to Polly Peachum is a typical middle-class banquet, featuring toasts, gifts, bad jokes, and gorging guests—except that it takes place in a stable and all the furnishings are stolen. Romantic love is reduced to lust and betrayal, with the relationship of Mackie and Jinny Jenny replete with pimping, whoring, sexual disease, and betrayal.

The play’s action follows a complicated network of double crosses: Macheath betrays Polly, Lucy Brown, and his gang; the whores betray Macheath twice; Peachum not only informs against Macheath but also sabotages his daughter’s chances for romantic bliss; and the plot climaxes with Mackie’s betrayal to the authorities by his supposed friend, the high sheriff of London, Tiger Brown. The Brown-Macheath friendship, added by Brecht to Gay’s plot, features a Kiplingesque ballad of their army bonding but is actually based on commercial advantage: Mackie gives Brown the goods on other criminals, while Brown, collecting a third of the reward, in turn provides police protection for Macheath.

Brecht sees every individual betrayed by an aggregation of other individuals, as well as by his own nature. Mackie, after all, commits consistent self-betrayals by following his compulsive libido and is brought down by his womanizing.

The Threepenny Opera is a second-rate achievement on Brecht’s part: Macheath is too winning a charmer to persuade the audience that he is a reprehensible criminal. More significantly, Brecht’s play fails to resolve a fundamental dilemma: Does human evil stem from an evil system (capitalism), or are there fundamental evils in human nature that systems merely reflect? The work’s glory is Kurt Weill’s brilliant music, which displays a high level of wit and rhythmic vitality. Thanks mainly to Weill, The Threepenny Opera is probably Brecht’s most frequently mounted play.

The criminal elements of London’s Soho district (thieves, beggars, and harlots) ply their various occupations while the balladeer sings about crime increases in the area, because of the reappearance of master criminal Captain James MacHeath (“Mack” or “Mackie the Knife”). The song concludes as Mack strolls down the street, causing occupants to quit their businesses and draw aside.

Jonathan Jeremiah Peachum, as notorious as Mack, heads a beggars’ organization that plays on the sympathies of wealthier citizens. Filch, an aspiring beggar, applies to Peachum for protection and a suitable costume and pays his fee under protest. Mrs. Celia Peachum ages the costume by staining it. Polly Peachum, their daughter, is out with a man she met a few days earlier. When Celia describes the man, Peachum realizes he is Mack the Knife. Celia tries to calm him, and they sing about how young love’s magic sours when the novelty wears off.

Mack escorts Polly to their wedding site, an empty stable that his bumbling henchmen, formally dressed for the wedding, ready for celebration by stealing furniture and even food for the banquet. Unfortunately, the henchmen have no taste and everything is wrong, even the dirge they sing as a wedding hymn to honor the couple. A minister comes to perform the ceremony, and Polly entertains everyone with a song about the revenge of the downtrodden on their social superiors. Mack’s best friend, Tiger Brown, chief of the London police, appears, and after reassuring Mack that his police record is wiped clean, the chief joins Mack in singing about being army buddies.

To her parents, Polly explains her marriage to Mack by saying that a “proper” man is not, necessarily, the “right” man. Peachum’s scolding is interrupted by the beggars, but he decides to bribe Mack’s harlots to turn on Mack. Polly boasts about the relationship between Tiger and Mack, but the Peachums reproach her by singing that “the world is poor and men are bad.”

Polly runs to the stable and warns Mack of plans for his arrest. He agrees to leave town, provided Polly will agree to collect his share from his thieves, send the money to his banker, and then turn the thieves over to the police. She agrees, and the newly arrived thieves swear their allegiance to her. She sings of her heartbreak at losing Mack.

Celia bribes Ginny Jenny to turn in Mack, and they plot his betrayal while singing “The Ballad of Sexual Submissiveness.” Mack hides out in Jenny’s brothel, where Jenny entertains him, and they sing about the days when they lived together. When the police raid the establishment, Mack attempts to escape through the window, but Celia and more police are waiting for him.

In prison, Mack refuses to acknowledge Tiger’s apologies for arresting him. After Tiger leaves, Mack attempts to bribe the jailer, singing about the “luxurious” life. Lucy Brown, Tiger’s daughter, visits Mack to tell him she is pregnant with his child. When Polly arrives, Mack pretends to scorn her so that Lucy will not tell her father about her pregnancy. Polly and Lucy bait each other in “The Jealousy Duet.” After Celia appears and drags Polly away, Mack persuades Lucy to help him escape. Tiger and Peachum discover Mack’s escape, and Peachum blackmails Tiger into rearresting him. Meanwhile, Jenny and Mack sing about how human beings live off one another.

At Peachum’s establishment, while the beggars prepare to work the crowds lining the streets for Queen Victoria’s coronation, Jenny and her girls come by to claim their reward, but Celia refuses to give it until Mack is reincarcerated. Tiger bursts in and attempts to arrest everyone, but Peachum outwits him and sends him to Sulky Tawdry’s to find Mack. Peachum sings about life’s futility, while Jenny sings about life’s absurdities. Polly visits Lucy and they become friendly, with Lucy admitting she is not actually pregnant. Celia brings Polly news of Mack’s impending execution and a widow’s veil.

Back in prison, Mack sings of his despair as he tries to borrow money from his henchmen to bribe his jailer. Polly arrives, but she has no money either. The only salvation for Mack is a queen’s pardon. Tiger comes with Mack’s last meal. Mack pays Tiger the protection money he owes, and all of Mack’s friends enter to say good-bye. There is such a crowd for his execution that no one is attending the coronation. Mack is standing on the gallows when, at the last moment, the queen’s messenger appears with a full pardon, which also gives Mack a castle and a pension. Peachum sermonizes the moral of the piece: “Life was hard, and pardons seldom came.” Everyone sings a reinforcement of the moral.