The Black Album. Metallica's eponymous 1991 album. A watershed moment in the band's career - an album that could be considered Metallica's "Greatest Hits."

The album debuted at number one in ten countries, and spent four consecutive weeks at the top spot of the Billboard 200, making it Metallica's first album to top album charts. It's the group's best-selling album, selling 30 million copies worldwide. In an album filled with great songs, one stands above the rest, a song that will be forever considered THE Metallica song.

Acclaimed by critics, the song is featured in all of Metallica's live albums and DVDs released after 1991.

It is among Metallica's most-played songs, having been performed live by the band over 1,500 times.

Of course, that song is "Enter Sandman". A song that has been covered myriad times, by artists as diverse as Motorhead, Richard Cheese, Weird Al Yankovich, Zebrahead, and Pat Boone.

But I think I've found my second favorite version of the song, and it's by a Bluegrass band called Iron Horse. I don't know how I missed it when it came out in 2003, but back then they released Fade to Bluegrass: Tribute to Metallica, a collection of ten Metallica songs done as only they could do them.

So, pull up a stool, grab a jar of moonshine and prepare yourself for the banjo stylings of Iron Horse.

And what does Kirk Hammett of Metallica think of Iron Horse?