Director Brett Morgen tells Billboard the album creates "a lighter portrait of Kurt than one might expect."

The director of Kurt Cobain: Montage of Heck says a companion soundtrack will include all the previously unreleased music featured in the film, plus a dozen additional tracks by the late Nirvana frontman when it's released in conjunction with the home-video version of the film in early November.

Filmmaker Brett Morgen says new material on the yet-untitled album will include "audio montages that Kurt Cobain created" and recordings of the artist talking in between the musical tracks, including "a sketch comedy routine featuring Kurt voicing all of the characters."

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Morgen put together the album while researching Montage of Heck, which involved immersing himself in more than 200 hours of recordings on 107 unmarked cassette tapes that Cobain left behind. After airing on HBO in May, the critically acclaimed film begins a theatrical run on Friday.

Although Universal Music Group, which is releasing the companion album, ultimately will determine the contents and track order of the album, Morgen says the compilation he turned in to the label "is curated to feel as though one were sitting in Kurt's living room watching him create over the course of an afternoon."

The song demos range "from thrash to ragtime and everything in between," says the director, though he notes, "Most of it is in a space that will be familiar to Nirvana fans."

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Unlike the dark nature of that band's signature tunes, Morgen says the companion album presents "a lighter portrait of Kurt than one might expect. You really get a sense of how happy he was simply by creating himself. His lyrics are really playful, and, at times, you can feel his smile and warmth coming through.

"These are all just Kurt by himself with the guitar," he explains. "These aren't multi-track, finished songs or work-ups, but they're extraordinary, and I think they provide a tremendous insight into his [creative] process. I think they further our understanding of Kurt, both as a musician and as a man." (How the songs will be titled is "to be determined," he says, given that the cassette tapes were unmarked.)

Kurt Cobain - Stomach from James Smith on Vimeo.

Morgen also says that when Montage of Heck is released on home video, the interview he conducted with Dave Grohl for the movie will not be included as part of the package. Due to Grohl's hectic schedule, Morgen was unable to sit down with the Foo Fighters frontman and former Nirvana drummer until after he had finished the documentary and decided not to add the footage because he was happy with the final cut as it is. "I don't think Dave Grohl is a DVD extra," Morgen says. "I think it would be disrespectful."