Image via Huffington Post

Image via Huffington Post

For some longtime Nirvana fans, part of the appeal of the upcoming Kurt Cobain documentary Montage of Heck is that it features unreleased music. The documentary also shows never-before-seen photos and behind-the-scenes footage, and reviews so far have been overwhelmingly positive. According to those who have seen it, it’s the most intimate look into the life of Kurt Cobain that has ever been presented to the public.

To make the Montage of Heck release even more exciting, director Brett Morgen has revealed that the movie’s accompanying soundtrack will feature a 12-minute acoustic Kurt Cobain song. He tweeted:

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The documentary will make its TV debut on HBO on May 4, and the companion book will be released on April 7. There’s no official release date for the soundtrack yet, but Morgen’s description of this unheard Kurt Cobain track should make it tempting to any Nirvana fan.

Morgen, though, is focused more on the movie than the music. He told Rolling Stone: “The score is all unreleased Cobain music. They don’t have titles. Before people saw the movie, there were these weird press releases focusing on the unreleased music. And it’s like: It’s a movie. We’re not going to stop it and play a song for four minutes.”

Related: 10 B-Sides, Rarities, and Demos That Every Nirvana Fan Should Hear