Metallica is an American rock band. After forming in Los Angeles in 1981, they released an opening run of albums in the 1980s—Kill 'Em All, Ride the Lightning, Master of Puppets, ...And Justice for All—that brought the underground sound of thrash metal into the mainstream. Their 1991 self-titled album, also known as The Black Album, won a Best Metal Performance Grammy Award and became their bestselling album, debuting at No. 1 on the albums charts in 10 countries on the strength of hit singles Enter Sandman,  The Unforgiven, and Nothing Else Matters.