If the only real legacy of the second N*E*R*D album was the moment in “She Wants to Move” where Pharrell warbles “her ass is a spaceship I want to ride,” Fly or Die would still be remembered fondly, albeit with a sort of memetic semi-ironic kind of fondness. It’s a damn sight more interesting a record than that, though, teeming with a guitar-heavy yet post-genre panache that proved the likes of Gnarls Barkley would someday be possible. They’re enthused with the possibilities of rock without getting all self-consciously rawk about it — you can hear as much singer-songwriter-tradition Ben Folds (“Jump”) and Steely Dan (“Breakout”) in the album’s post-alt DNA as you can in guitar heroes like Lenny Kravitz (“Maybe”) and Red Hot Chili Peppers (“Backseat Love”). Considering how often these songs re-center a primordial notion of rock less as its own self-contained world than as a subgenre of R&B, you can forgive Pharrell if he still sounds a little short on vocal chops at this point in his career. But even then, the oddly delicate, even vulnerable timbre to his voice makes songs like the teen-angst title cut and the your move, Green Day anti-war power-pop flip-off “Drill Sergeant” strong arguments for the musical effectiveness of naive pop idealism in a world of cynics.