Metallica is celebrating an anniversary this week.

FOX's Laura Ingle explains in "Bonus Track":

Metal fans want to feel old? The album that brought us the rock anthem 'Enter Sandman' was released 25 years ago this week. Otherwise known as the "black" album, the record was the biggest breakthrough for any metal act in history.

It was the first single released in the summer of '91, the song becoming a permanent fixture on playlists, entrance music in sports, talk radio shows and was even used by NASA mission control to wake up shuttle astronauts. 

Metallica is currently recording its tenth album and this weekend will perform in Minnesota at the newly open U.S. Bank Stadium, becoming the first rock band through the doors to play the venue, selling out the show in minutes.

Drummer Lars Ulrich telling Rolling Stone Magazine their happy and appreciative the fans still show up:

(Ulrich) "And the fact that we can sell 50-55,000 tickets to a show still blows our minds."

I'm Laura Ingle and that's your "Bonus Track".

Follow Laura Ingle on Twitter: @LauraIngle