The parody subgenre once gave us comedy classics like Young Frankenstein, Airplane!, Top Secret!, and The Naked Gun. This glorious tradition has been disgracefully violated in recent years by the likes of the cleverly titled Epic Movie and Date Movie. (As for the latter -- a spoof of comedies? Outstanding idea!) Walk Hard: The Dewey Cox Story, a parody of musical biopics like Walk the Line and Ray, marks the pretty damn triumphant return of the spoof film. The movie also marks the return of Judd Apatow, and I'm pleased to report that Walk Hard completes a 2007 hat trick for the man. It easily joins Knocked Up and Superbad to form the unholy trinity of the year's superior comedies.

Starting in fictional rock star Dewey Cox's boyhood Tennessee home and ending some sixty years later after his bouts with women, booze, and pills, the film traces the blood pumping rise...of Cox. (First and last Cox joke, I promise.) The script gets Cox making music quickly, and good thing. I'm not sure why the first ten minutes of Walk Hard were released online as part of the marketing plan, they're easily the weakest scenes of the film. But once John C. Reilly enters the picture, portraying Cox at age fourteen despite being 25 years older (a dig at Kevin Spacey in Beyond the Sea?), it's pretty much smooth sailing.

Reilly really is fantastic here. He nails all the same beats he would have had to hit in an actual biopic, but he does it all while being incredibly funny. It's a finer and much more difficult performance than, say, Joaquin Phoenix's in Walk the Line, although Reilly's Golden Globe nomination (for Best Actor in a Comedy or Musical) aside, he won't get half the respect. Reilly is so good, in fact, that the rest of the cast suffers in comparison. Jenna Fischer is great at being quietly mortified on NBC's The Office, but big-budget broad Hollywood comedy is proving not to be her niche. Reese Witherspoon was funnier in Line, and that was a drama. To be fair, a large part of Fischer's problem, as it was in this year's Blades of Glory, is that she isn't given so much as a single solid joke to work with. The male-dominated comedy world needs to figure out how to write for funny female leads, and fast. Kristen Wiig fares a little better in a showier, trashier, smaller role as Dewey's first wife. She rips every available chuckle out of the script, and if I were casting the thing I would have given Fischer's role to Wiig and Wiig's role to Jamie Pressly. Strangely, nobody asked my opinion in putting together the film.

Dewey's band, the Hard Walkers, is made up of Upright Citizens Brigade's Matt Besser and Saturday Night Live veterans Tim Meadows and Chris Parnell. These are three very funny men, but aside from Meadows' epic drug joke, they're not given a lot to do either. That's a shame, because I recently watched Hot Rod, and in just a few scenes Parnell totally steals the film away from his co-stars. I was eager to see him cut loose again. As for the other roles, pretty much every speaking part is some sort of celebrity cameo. This strategy often works, as in the uproarious scene with "The Beatles" -- played by Jack Black, Paul Rudd, Justin Long, and Jason Schwartzman. Other times -- particularly the terribly unfunny Jonah Hill appearances and a long and dull scene with the generally brilliant Jane Lynch -- it feels like lame sequences weren't cut due to friendships with the performers.

The script, by Apatow and director Jake Kasdan, is funniest when it zeroes in on the specific reasons these biopics are so ridiculous. Indeed, you won't watch one the same way again. But the screenplay has some problems. The Brian Wilson-inspired portion of the film falls particularly flat, and having read Wilson's autobiography, I'm not sure why. The filmmakers had a lot of juicy material to play with there. There's a lot of slapstick in Walk Hard, and physical humor ain't a strong suit of Apatow or Kasdan. There's also a bit too much reliance on repetition. If a bit works the first time, they'll repeat it again and again throughout the film until it doesn't. And if a bit doesn't work the first time, you'd better believe it's not funny the tenth.

The problems are quickly washed away by laughter though, and for the most part Walk Hard is a great mix of the smart and the stupid, the sweet and the scatological (there's a bit of nudity you won't soon forget, no matter how hard you try). And unlike most comedies, Walk Hard doesn't peter out at the end. In fact, some of the funniest stuff comes in the home stretch -- hilarious gags like the terrible old age makeup, the rap video, the tribute ceremony, and a Temptations joke so unbelievably corny and uncool I wanted to stand up and applaud.

The music -- by a gaggle of crackerjack musicians including Dan Bern, Mike Viola, and the great Marshall Crenshaw -- is terrific, and really carries the film over its rough patches. It might surprise audiences that the lyrics are not particularly funny -- Tenacious D this is not. In fact, the funniest song on the soundtrack album, the wildly offensive "Dear Mr. President," is not performed in the film at all. But the fairly play-it-straight attitude of most of the songs provides the illusion of reality that helps ground the film as it dips into surrealistic Anchorman territory. And Reilly's takes on Johnny Cash, Elvis Presley, Roy Orbison, Bob Dylan, and The Beatles are highly impressive. The guy's got genuine singing chops.

Ultimately, Walk Hard is a mixed bag, as all spoof movies are. Do the hits outweigh the misses? Absolutely. Do Apatow and Kasdan nail their targets? With a vengeance. Did I laugh? A lot. Is it funnier than Knocked Up and Superbad? It's a completely different style of comedy, but I'll say I laughed less here than in Knocked Up and more than in Superbad. It may not be the next Naked Gun, but it's a long way from Musical Biopic Movie.