When A Chorus Line opened on Broadway in 1975, it turned heads with its pseudo-documentary format, fictionalizing personal stories that director Michael Bennett had collected in taped conversations with veteran dancers. This film by James Stern and Adam Del Deo is a real documentary, and as it follows a handful of performers through auditions for the show’s 2006 revival, it reveals how strongly today’s showbiz hopefuls have internalized A Chorus Line, turning its reportage into myth. Modeling the movie after the show itself grows problematic near the end, when Stern and Del Deo, anticipating that climactic, gold-suited kick line, try to whip us into a frenzy on opening night. But their history of the show, studded with clips from Bennett’s original audiotapes, adds a fascinating subtext: in chronicling Broadway, A Chorus Line changed it forever. PG-13, 96 min.