So far, we know that the Brett Morgen-directed Kurt Cobain documentary Montage of Heck will feature unreleased music, including a 12-minute acoustic Kurt Cobain song in the accompanying soundtrack. A companion book comes out April 7, and the movie premieres on HBO on May 4. The trailer for the documentary is now available, and shows some exclusive photos and behind-the-scenes footage of Kurt, Courtney, Frances Bean, and more. Watch it above.

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