Premise: The Aristocrats is a 2005 American documentary comedy film about the famous dirty joke of the same name. It was conceived and produced by comedians Penn Jillette and Paul Provenza, edited by Emery Emery, and released theatrically by TH!NKFilm. The film is dedicated to Johnny Carson, as "The Aristocrats" was said to be his favorite joke.
Hypothesis: The Aristocrats is about a dirty joke that existed before the film was created.