The best part of this musical biopic parody is the music. The jokes? Well, they're not bad, but they're mild chuckles, not belly laughs.
In the tradition of Ray, Walk the Line, and La Vie en Rose, Walk Hard gives us the tragic life story of a famous musician. This time, it's Dewey Cox (a rare starring role for perennial second banana John C. Reilly). And if you've seen any of those other movies, you know the broad outlines of the story -- distant father, tragic death of a young sibling, early success, early unhappy marriage, drugs, divorce, redemption at the hands of beautiful second wife, late-career comeback.
We get all of those points here, played for laughs. Dewey's younger brother dies, for instance, when Dewey accidentally slices him in half with a machete ("You're gonna make it, Nate!" "I dunno, Dewey; I been sliced in half pretty bad here."), and Pa Cox spends the rest of the movie muttering "the wrong kid died."
There are a host of cameo appearances -- Frankie Muniz as Buddy Holly; Jack White as Elvis; Jack Black, Paul Rudd, Justin Long, and Jason Schwarzman as the Beatles -- and some nice supporting turns from Kristin Wiig, Jenna Fischer (as wives #1 and #2, respectively), and Tim Meadows as the drummer whose "stay away from these drugs, Dewey" warnings always turn out to be more enticing than threatening.
Best of all are the songs. All of Dewey's music is newly written for the movie, and the large crew of songwriters has done a fine job of creating songs that sound like authentic relics of their eras. Reilly does a reasonably good job of singing them. (He has, in a sense, the opposite problem from Johnny Depp in Sweeney Todd, in that he has a voice too well-trained to be a really convincing pop singer.) His mumbling-Dylan impression is funny, and he does a surprisingly strong evocation of Roy Orbison in a lovely song called "A Life Without You."
When it's all over, though, Walk Hard is a mild amusement and not much more. I can't recommend that you rush out to see it in the theaters; it'll play just fine on DVD or cable TV.