The mood of The Beggar’s Opera is lighthearted and merry, though this mood is occasionally darkened by John Gay’s biting satire of London society and the unequal treatment received by the rich and the poor under the law. These contrasting moods are exemplified in a short, comedic verse sung by Peachum after learning of his daughter’s marriage to the criminal Macheath:
A Fox may steal your Hens, Sir,
A Whore your Health and Pence, Sir,
Your Daughter rob your Chest, Sir,
Your Wife may steal your Rest, Sir,
A Thief your Goods and Plate.
But this is all but picking,
With Rest, Pence, Chest and Chicken;
It ever was decreed, Sir,
If Lawyer’s Hand is fee’d, Sir,
He steals your whole Estate.
These short, repetitive, rhyming lines establish a sing-song quality that stands in stark contrast to the grand arias of Italian opera. Like the play’s other short songs and verses, this passage is lighthearted and amusing despite its serious subject matter. Peachum’s verse reveals a dark and cynical understanding of London society in the early 18th century that is barely concealed by the lighthearted mood. He suggests that criminal activity is rampant and that even family members—fathers and daughters, husbands and wives—cannot trust each other. Further, he insists that these small-scale forms of thievery pale in comparison to corruption in the legal system. Peachum's verse mirrors the mood of the play more broadly, which conveys sharp social criticisms in a fun and jovial manner.