As a stand-alone documentary on battle rap, "The Battle for L.A." suffers from a self-important myopia that nearly derails it. However, the little "Vol. 1" at the tail end of the title just about redeems it when you realize that this is just the first installment in director Darren Doane's examination of the real hip-hop underground, with future movies to focus on New York and beyond. (Doane is Los Angeles-based, so you really can't blame him too much for starting in his own backyard.) With a lot of vérité shots and breakneck edits, "The Battle for L.A." can be a bit visually taxing, but the verbal energy flying from the mouths of these street poets more than makes up for it. Shot over three days, the film is focused firmly on the phenomenon of battle raps, rather than attempting a take on hip-hop culture at large. Venomous and verbose, the battles are dramatic and engaging and, begrudgingly admitted, Doane's visual style adds a lot to the tension. It's sweaty, emotional and largely unscripted, three elements not often found in mainstream hip-hop. If nothing else, "Footsoldiers"s is a gratifying document of what it truly means to be keeping it real.