Five years after the first-ever authorized documentary about Led Zeppelin was first announced — and nearly three years after it premiered at the Venice Film Festival — the long-awaited film is finally preparing to take flight to the big screen. Sony Pictures Classics announced Wednesday that it has acquired Becoming Led Zeppelin , a “hybrid docu-concert film” directed by Bernard MacMahon and made with the full cooperation of the band. The documentary features new interviews with Zeppelin’s