Some 14 previously unheard NIRVANA recordings, comprised of demos and alternate mixes, mysteriously and briefly surfaced online over the weekend. According to The Pulse Of Radio, the source of the recordings was unknown, although Reddit users were able to glean some information about them. At least four were recorded at the legendary Sound City during the 1991 “Nevermind” sessions, while others date from the 1993 sessions for “In Utero”.

By Monday afternoon (August 3), however, all 14 tracks had been taken down due to copyright infringement notices from NIRVANA‘s record company, Universal Music.

Among the tracks were a “Sappy” outtake, a new “Verse Chorus Verse” mix, two versions of “Old Age”, a version of “Heart-Shaped Box” containing a longer guitar solo, plus demos of “I Hate Myself And I Want To Die” and “Scentless Apprentice”.

It’s possible that the tracks were leaked from a companion album to the documentary “Kurt Cobain: Montage Of Heck” that the film’s director, Brett Morgen, said was coming out at some point this year.

Morgen said that the album would contain unreleased material from late NIRVANA frontman Kurt Cobain‘s personal archives, which were housed in a storage facility that Morgen was given access to for his film.

He told The Pulse Of Radio how he pulled the material together. “There were several archives we drew on for this film,” he said. “There was Wendy‘s [Cobain, Kurt‘s mother] archives, there were Frances [Bean Cobain, Kurt‘s daughter] and Courtney‘s [Love, Kurt‘s widow] archives. [NIRVANA bassist] Krist Novoselic turned over a ton of material. And I knew for sure that this movie needed to live inside the storage facility.”

Morgen said that he discovered nearly 200 hours of previously unreleased audio from Kurt in the musician’s personal archives while making the film.