Most of the best gags are in this stretch. We have Dewey singing "You Got to Love Your Negro Man" at an all-African-American club. There's his impromptu playing of the title song at a recording studio (The band says, "We don't know this song," to which Dewey responds, with the realistically unlikely but genre-ready line, "Just follow me."). There's the pressure of having to follow the Big Bopper, Buddy Holly, and Elvis. And, of course, there are the temptations of the road. Tim Meadows plays Dewey's drummer, who gets the biggest laugh in the slowing movie as he tells Dewey not to smoke pot&mash;and then tells him every reason why he should.

The running gag of Dewey's introduction to new assortments of drugs is quite funny and in the spirit of poking fun at genre necessities. The rehab scene, in which Dewey can't decide how many or how few blankets he needs, is not. When he meets good, Christian back-up singer Darlene Madison (the always adorable Jenna Fischer) and sings "Let's Duet" (a song full of pauses in potentially inappropriate spots), it pokes fun at the sexual tension. When they begin to hit each other in an abusive form of foreplay, it does not. The songs are solid and catchy and move along as Dewey's career goes through the decades (his '60s Dylan-esque nonsense lyrics are funnier than attempts to make fun of LSD-inspired epics), and he meets a lot of famous musicians, real and fake.

He stops in with the Beatles in India (Jack Black, Paul Rudd, Justin Long, and Jason Schwartzman play the Fab Four in my order of preference) and takes a Yellow Submarine type acid trip. It's a funny scene, but it goes on too long, which another problem the movie has. Stranger still are the fact that all record producers are Hasidic Jews, Dewey's love for his chimpanzee, and a random penis that takes the forefront camera right in the aftermath of Dewey's first drug-induced party.

Apatow and Kasdan's effortless satirical moments are few and far between in Walk Hard: The Dewey Cox Story. Too many of the jokes are like Dewey's temper tantrums in which no piece of furniture is safe: blunt-force comedy. It's too scattershot to work on the whole.