As is now customary, last night's Big Four show at Yankee Stadium featured a "jam" with members of all four bands -- Metallica, Megadeth, Slayer and Anthrax -- taking the stage to perform a classic song. Usually, the track has been Diamond Head's "Am I Evil?," but last night, the bands played a song they had never before played together: Motorhead's "Overkill."

In case you've been living under a rock, the November issue of Guitar World features the members of the Big Four by way of an epic cover shoot that took place in Milan, Italy. Now, you can check out an exclusive gallery of outtakes from one of the most historic GW covers of all time below.

In the following video, Guitar World's Jimmy Brown shows you how to play the main riff to "South of Heaven," the title track to Slayer's 1988 classic.

We've been teasing you for the past couple of weeks with trailers for the November 2011 issue of Guitar World, which features the members of the Big Four. Now, you can check out the cover -- in all its glory -- below.