Walk Hard: the Dewey Cox Story (15)

The conventions of the musical biopic are ripe for ridicule, but it would take a much smarter, subtler parody than Walk Hard to nail them. John C Reilly stars as Dewey Cox, overcoming a traumatic accident in his Southern boyhood to take America by storm with his powerhouse rock'*'roll. As his fortunes seesaw through haircuts, drugs, wives and children we count off the biopic sincerities of Ray and Walk the Line being wildly spoofed, with rock's other famous crash-and-burn victims (eg Brian Wilson, Elvis) thrown in for good measure.

Sometimes its sheer silliness hits the funny bone, such as the scene in which Cox meets The Beatles – hilariously accented and very far from fab. But too much of it is effortful and repetitious, to the point where the stuff being parodied becomes as irksome as an actual biopic. The screenwriters – director Jake Kasdan and Judd Apatow – adopt the approach of chucking everything at the wall and seeing what sticks. Not much of it does, I'm afraid.