In an exclusive look inside their upcoming issue, Rolling Stone has posted a previously unheard Kurt Cobain demo from the forthcoming documentary, Kurt Cobain: Montage of Heck. We also get a look at David Fricke’s upcoming cover story with the late Nirvana frontman’s daughter, Frances Bean.

Frances, who serves as executive producer of the upcoming film (hitting select theaters on April 24 and airing on May 4 on HBO), speaks candidly about the father she never knew, but whom people undoubtedly see when they look at her. “For 20 years, my dad has been like Santa Claus, this mythical figure,” she tells Rolling Stone. “People come up to me and say, ‘Your dad’s so cool.’ And I don’t know him. I want to present Kurt the man.” Read snippets of Frances’ interview here, and stream Cobain’s demo above.