Metallica's 1991 album, commonly called The Black Album, spent four consecutive weeks at number one on the Billboard 200.
The Billboard 200 ranks albums and extended releases in the United States, unlike the Billboard Hot 100, which ranks individual songs. Metallica's achievement therefore refers to the performance of the complete album rather than a single such as “Enter Sandman.”
The album was Metallica's first release to top the Billboard album chart. It debuted at number one and remained there for four consecutive weeks, a major milestone for a band previously identified primarily with the underground and thrash-metal scenes.
Its chart success helped bring heavy metal to a broader mainstream audience. The record also debuted at number one in several other countries, reinforcing that its impact was international rather than limited to the United States.