The ne plus ultra of “guilty pleasures,” the Step Up movies are willfully naive, awkward, and irresistible. Directed by Scott Speer, the fourth iteration, Revolution, throbs with possibility as an underground collective called “the Mob” stages elaborate dance numbers in a bid to capture an American Idol-like Internet bounty. Expressively deploying the stereoscopic 3D imagery, Speer has the vertiginous choreography shifting into the abstractly beautiful, playing off the light and color at an art gallery or a Monet-influenced battery of corporate drones, to achieve a lyrical and kinetic propulsive flow. The inventive stylization and avant-garde flourishes counteract the actors’ technical limitations and the ludicrous framing story involving the collective’s leader (Ryan Guzman), his furtive romance with aspiring dancer Emily (Kathryn McCormick), and her father’s corporate hooliganism. At its best, it embodies emotion through movement.