Demos, B-sides and concert recordings are among the rarities that will be included on not one, but two deluxe 20th anniversary editions of Nirvana's 'Nevermind' from Universal Music Enterprises.

Originally scheduled for a Sept. 19 release, the digitally remastered and beefed-up 'Nevermind' packages will now drop on Sept. 27 — 20 years and three days after the original album arrived.

Here are the recently announced details: The four-CD, one-DVD Super Deluxe Edition will be limited to 10,000 numbered copies in North America and 30,000 more for the rest of the world. In addition to the remastered original album, which was produced by Butch Vig and mixed by Andy Wallace, it will contain a version of 'Nevermind' mixed by Vig.

Also included are Nirvana's entire Halloween 1991 concert from the Paramount Theatre in Seattle (on CD and DVD), plus demos the band recorded with Vig, rehearsal recordings of 'Smells Like Teen Spirit' and other key tracks, studio and concert B-sides, previously unreleased BBC recordings as well as a 90-page bound book.

In addition, the two-CD Deluxe Edition of 'Nevermind' includes the digitally remastered album, plus the B-sides, the demo sessions, the rehearsals and the BBC sessions.

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