Metallica shares rough mix of "The Unforgiven" from Spring of 1991

Metallica isn't letting up in the celebration leading up to the 30th-anniversary reissue of 'The Black Album' its seminal self-titled record from 1991.

The latest morsel of history is a rough mix of "The Unforgiven" that's dated from May 14 of 1991, a few months before the 'Black Album' was released. The track is part of the two-disc Rough & Alternate Mixes set which comes with the forthcoming album reissue.

While the mix is indeed rough compared to the version that ended up on the Black album, Metallica junkies will surely enjoy a new perspective on the classic song.

Earlier this summer, Metallica unveiled a rehearsal recording of "Holier Than Thou," an alternate studio take of "Sad But True" from February 1991 and a wordless demo version of "Enter Sandman" from July of 1990.

'The Black Album' was an instant hit when it was released on August 12, 1991. The album produced several rock radio and MTV hit singles and vaulted the band into a new stratosphere as the most successful heavy metal act of all time.

The 30th-anniversary edition of the 'Black Album' arrives September 10, along with The Metallica Blacklist, a massive compilation of covers of 'Black Album' songs by various artists to raise money for charity.

Photographer Ross Halfin's 'Metallica: The Black Album In Black & White' photo book is set to arrive on October 19.