Filmmaker Brett Morgen, working with extensive personal journals and private videos and audio recordings provided by Kurt Cobain’s family, paints a portrait of the Nirvana front man that’s not always easy to watch, but does provide deeper glimpses than most celebrity film biographies. The abstract drawings in Cobain’s journals, especially the ones reflecting his many moods, reveal a lot. Sadly, home-video footage of Cobain and his wife Courtney Love, wallowing in drug addiction while trying to tend to their baby daughter, Frances, reveals even more. Concert footage is shown sparingly, but the contrasts are stunning: There are scenes of the grunge band’s meager beginnings in tiny clubs, giant stadium-size Nirvana spectacle shows, and, most effectively of all, an intentionally stripped-down MTV Unplugged appearance, where Cobain’s vocal on “All Apologies” is even more haunting in retrospect than it was at the time. The title of this film, by the way, comes from the name Cobain gave to his audiotape collections of music and musings: Montage of Heck.