A new documentary on Kurt Cobain by filmmaker Brett Morgen, who had full access to a collection of home movies, art and audio belonging to the late Nirvana frontman, is getting good reviews from many who've screened it, including those at the most recent Sundance Film Festival. The soundtrack of the film also features a 12-minute acoustic track by Cobain that was never released. The movie is now making the rounds of film festivals and will be aired on HBO May 4.