Macheath the gangster marries Polly Peachum against her father's wishes, and the London underworld erupts. Brecht and Kurt Weill rewrote John Gay's 1728 Beggar's Opera as a Weimar-era attack on bourgeois morality. "Mack the Knife" became a jazz standard. The show's argument that criminals and capitalists are interchangeable still plays.

The case for it, the case against, and the rest of the canon open with Pro.