Bartholomew Fair is considered an experimental play for many reasons, chief among which is its induction. An induction was similar to a prologue, in that it preceded the play and shed some light on what audiences were about to see. Inductions in the theater typically worked as commentary on the events of the play proper, and may have even introduced audiences to one or two characters who would appear in the play itself. They were not uncommon on the early modern English stage, and indeed featured heavily in plays (especially tragedies) written in the late sixteenth century.
The induction in Bartholomew Fair, however, is quite unique. Not only does it introduce a comedy (usually, city comedies required little introduction), but it also features a meta-theatrical performance by characters who never appear again in the play: a stage-keeper, a bookkeeper, and a scrivener. The stage-keeper appears first, announcing that the play is not to his taste and that he does not care for the playwright. When the scrivener and bookkeeper enter, they chase the stage-keeper off the stage and tell him to stick to cleaning the theater. Then, the bookkeeper has the scrivener read a contract they have written for the audience: the audience has paid a small price to see the play, and they are free to like or dislike it, but they should not read too seriously into the characters, events, or remarks made. The contract prepares audiences for a mediocre performance rather than an engrossing adventure or tragedy.
This preamble to the play proper is important because it establishes the ironic tone that dominates most of Jonson's work. Not only does Jonson allow himself to be openly criticized as a playwright (by a low-class stage-keeper no less), he also builds into the structure of the play an acknowledgment that the audience, the actors, and the playwright will all share in an experience together for the next three hours. By preparing the audience with the "contract," Jonson turns the focus of the play on sociality, which is, of course, one of the central themes of Bartholomew Fair and Jonson's dramatic oeuvre more generally.
