Neoclassicism, as its name implies, drew on classical concepts to create a new framework for arts and culture. Using Aristotle as their guide, neoclassicists established a system to determine what made "good" art. A "good" neoclassical comedy, then, had to feature all of the following components:

• The play must take place over 24 hours.
• The play's action must occur in a single location.
• The play should feature a single plot.
• The characters should be believable.
• The characters should act in a upstanding manner (lead characters should also be members of the aristocracy).
• The play must be comedic, not tragicomic.

In The Beggar's Opera, John Gay immediately undermines the neoclassical system by creating a new kind of theatre: the ballad opera, a combination of an opera and a play. In its combination of styles and forms, The Beggar's Opera would be rejected by most as a neoclassical comedy.

The actual content of The Beggar's Opera, too, is problematic as a neoclassical comedy. While the play's action takes place over a single day, it also features numerous locations, a handful of side plots, and characters who act well outside the norms of believable behavior. This undermines many aspects of a traditional neoclassical comedy.

In addition, not only were Gay's leading characters, like the Peachums, Polly, Macheath, and Lucy, not members of the aristocracy, but they also acted without decorum. A comedy whose leading characters are thieves, prostitutes, and corrupt business owners who act despicably would not be accepted by the rules of neoclassicism.

Gay amplified the lack of decorum in The Beggar's Opera by using existing tunes in the opera, most of which were well-known as sexy, sleazy, or ignoble. Then, he paired sweet, modest lyrics with them, creating a powerful disconnect. This would be shocking to audiences and undermine the neoclassical concept that genres should remain separate.