So much petty drama has clouded the release of Michael Rapaport's A Tribe Called Quest documentary. One version of the backstory casts the first-time director as a doofus actor wannabe who persuades the seminal but privately splintered hip-hop crew to participate in a consummate career doc. After two and a half years of the corny B-lister shadowing and interviewing the foursome, the final product gets accepted to Sundance, and suddenly the group's de-facto leader, Q-Tip, reneges his support via Twitter. When three-fourths of ATCQ boycott Park City and later whine on MTV about an errant production email they received conspiring "We'll fuck them," it's not particularly surprising. The wrinkle in this retelling is that Beats, Rhymes & Life is a phenomenal documentary. Making a "love letter" to his all-time favorite musicians, Rapaport devotes the film's first half to deftly curated archival material, golden-age hip-hop perspectives, and testimony from an impressive constellation of Tribe's peers and pupils. Then comes the film's second half, focusing on the disintegrated ties between boyhood friends Tip, who has evolved into dapper VH1 royalty, and his 20-year collaborator, Phife Dawg, who's grown to resent how Tip's calculated swagger shrinks him into a sidekick. Pitbull-stubborn and type-one diabetic, Phife becomes the movie's wounded dark horse. (Rated R)