Metallica's 1991 album Metallica, known as The Black Album, is the band's fifth studio album.
It followed Kill 'Em All, Ride the Lightning, Master of Puppets, and ...And Justice for All. Those four earlier records established Metallica as a leading thrash metal band before the 1991 album adopted a slower, heavier, and more streamlined approach.
The fifth-album position is important because Metallica marked a major stylistic and commercial transition. The band retained its heavy sound, but many songs used more concise structures and a more polished production style than the preceding records.
Later studio albums included Load, Reload, St. Anger, Death Magnetic, Hardwired...to Self-Destruct, and 72 Seasons. The phrase “The Black Album” is an informal nickname for the self-titled fifth album, not the name of a separate release. That distinction helps separate it from Metallica's other studio records.