This loving, almost hagiographic tribute to the art of improvised rapping and battling does not feature Eminem. There is no footage from 8 Mile or BET’s “Freestyle Friday,” and the entire documentary seems to exist in some alternate universe where hip-hop is still the runty underdog. A lot has changed in the 10 years since Kevin Fitzgerald began this labor of true-school love, and it’s the film’s quaint sense of anachronism that makes it so precious: Folks much more famous now than when first interviewed wax poetic about historic freestyle sessions; rappers who have since given up art for commerce hunger for a chance to show off in front of the camera, any camera; myths are created around important street corners or, in the case of Los Angeles’s Project Blowed, in the back of a health food store. Despite cloying narration, Fitzgerald’s footage and interviews are fantastic: A scene of Tupac and Biggie freestyling over Tanqueray is especially gripping, as are the sequences of freestyle legends Craig G and Supernatural watching younger versions of themselves duke it out. Like both pairs of old warriors, we’re left to wonder if it was all so simple then.