Next week, Brett Morgan's documentary about Kurt Cobain, Montage of Heck, will be released in US theatres as part of its worldwide screening plan. Although the highly acclaimed film recently premiered on HBO, Morgan has added a little something for the occasion: a previously unreleased Kurt Cobain song.

The bootleg is said to be reminiscent of the Beach Boys' Brian Wilson due to Cobain's falsetto, and although he explained it was included in the film without altering the treatment, he refused to say exactly where the new tune was added: "I don't want to get people out there bootlegging it on their cell phones."

Brett Morgan recently revealed that a new album of Cobain's originals had been discovered while filming the documentary, and that it was going to get a proper release. However, no further news have been shared.