Irving uses dramatic irony to highlight how Ichabod Crane is disconnected from reality. One key example is the gap between Ichabod’s estimation of his own skills as a singer and dancer and the audience’s estimation:
Ichabod prided himself on his dancing as much as upon his vocal powers. Not a limb, not a fiber about him was idle; and to see his loosely-hung frame in full motion, and clattering about the room, you would have thought Saint Vitus himself, that blessed patron of the dance, was figuring before you in person.
Ichabod is proud of his dancing skills, but the way the narrator, Diedrich Knickerbocker, describes Ichabod in motion is far from flattering. In this passage, he comes across more as a frenetic, “clattering” bag of bones than a suave suitor. The reference to Saint Vitus is another subtle dig from Knickerbocker. Catholics invoke Saint Vitus against a neurological disorder called “chorea”—also known as “St. Vitus Dance”—and one of chorea’s symptoms is uncontrollable jerking of the limbs. The contrast between reality and Ichabod's self-perception encourages readers to distrust Ichabod’s worldview, from his certainty that he is succeeding with Katrina to his belief in the supernatural.
The dramatic irony in the dancing scene is an example of how "The Legend of Sleepy Hollow" blends fact and fiction. Knickerbocker has a vastly different account of Ichabod’s dancing than Ichabod does, and the reader can only guess at the effect Ichabod's frenzied movement is having on Katrina, or on the Black people who are watching him through the windows. Irving writes that they are “gazing with delight at the scene,” but is this another one of Ichabod’s delusions? Are their “delighted” smiles really signs of derision? And who is Knickerbocker to tell the reader how these Black observers felt watching white landowners at a lavish party? During the dancing scene, the supposedly true historical account that is "The Legend of Sleepy Hollow" breaks into a series of disjointed, opposing fictions.
