The Kurt Cobain documentary Montage Of Heck aired on HBO a few months ago, and since then, a slightly different cut of the movie has shown in a few theaters. That theatrical cut includes an unreleased, untitled Cobain song that wasn’t earlier versions of the movie. It’s clearly a home demo, and it’s hard to believe that Cobain would’ve ever had plans to release it, at least not anything like the version that made it into the movie. (It’s got Cobain singing in a jokey Frankie Valli falsetto.) But even on a song like that, Cobain used the quiet-to-loud structure. As Alternative Nation points out, someone made a cell phone recording of the song during the movie’s credits, and you can check it out below.

The Montage Of Heck DVD and an album of unreleased Cobain solo music are apparently both set to come out 11/6.