The riff: Sung by Crow after he makes a little drumroll noise, as the titular chicken of the film’s title begins to crack its way out of its egg.
The explanation: Crow is parodying the television intro to the first season of “The Partridge Family.” Sung to the tune of “Come on get Happy,” (Is this the same song?) it shows an egg cracking, which reveals the show’s title card and opening credits.
Novelty factor: I recognize the tune, of course, because everyone knows “Come on get Happy.” But honestly? I wasn’t even aware of its Partridge Family connection. Re-runs of The Partridge Family were not the kind of thing that adolescent Jim was interested in during the 1990s.