Many have tried to tell Kurt Cobain’s story, but very few had the kind of access Brett Morgen was granted for his documentary on the Nirvana front man, Montage of Heck. It was made with the full cooperation of his family and friends — Courtney Love and their daughter, Frances Bean, served as executive producers — who gave the director permission to use never-before-seen home videos, Cobain’s personal artwork, interviews, and even unreleased songs. Its trailer features all of that, as well as gorgeous renditions of “All Apologies” and “Smells Like Teen Spirit” that you’ll probably have stuck in your head all day. One person you won’t see, though? Dave Grohl, whose interviews Morgen said he had to cut because they were filmed too close to his deadline. HBO will air the doc on May 4.