The thumping of Eminem's 1999 "The Real Slim Shady" sets the soundtrack for the new "21 Jump Street." As the film opens to "Shady" strains, the camera follows an Eminem lookalike from the back. When he turns around, he's a not-so Slim Shady nerd named Schmidt (Jonah Hill). On the opposite end of the high-school pecking order is football jock Jenko (Channing Tatum) who is barely passing high school, but who will no doubt be prom king.

A few years later, the two meet again at the police academy. While Jenko is ready to kick some butt, Schmidt can't even shoot straight. The two are assigned to a bicycle cop beat. Their first big bust could come when they spy a motorcycle gang smoking pot in a park. But Schmidt's timidity and Jenko's brawn, but no brains, ends up getting them reassigned. Their next stop? Going undercover into a high school to help stop the distribution of a new designer drug.

As a quasi spoof on the 1980s FOX television series "21 Jump Street," the film is like an extended sketch comedy bit from "Saturday Night Live" or "MAD TV," but there are so many riffs on past and current pop culture, there's enough to easily fill two hours with hilarity.

The script by Michael Bacall ("Project X") and the film's co-star Hill show a definite Judd Apatow influence with the same irreverent, devil-may-care attitude coming through that made "Knocked Up" and "Superbad" such hits.

When the underachieving cops end up at the school, they find that things have changed. The dealer of the designer drug (David Franco, James' younger brother) is an eco-friendly, Valley guy who writes folk songs about recycling. Jabs at "Glee," Michael Bay-inspired Hollywood car chases where everything blows up (nothing does here), YouTube, cell phones, and, of course, cheesy 1980s TV cop dramas, are the film's go-to targets, along with so many more it's difficult to follow them all, let alone list them.

The jokes are also infused in the casting. Ice Cube plays his role to the hilt as a foul-mouthed police captain, since the hip-hop star is known for his anti-police lyrics. Cube has softened a bit, so the sting of his anarchy doesn't resonate as much as it might have a few years ago. Even co-star Tatum has a lot of fun with a number of references to his reputation as a Hollywood hunk.

Hill and Tatum are a quirky comedy duo. Tatum is surely an unlikely choice to go up against Hill, but they couldn't be more in sync, especially when they are jamming each other's fingers down their throats in an off-the-wall bathroom scene. Their bromance hits a high point when Schmidt asks Jenko to the prom.

Part "Animal House," part "Harold and Kumar Go to Police Academy," "21 Jump Street" is no "Brady Bunch Movie" send up. It's smarter than that. Here's a comedy that was able to sign Johnny Depp to play a caricature of himself. Now that's genius.