The "Black Album," officially titled "Metallica," is the self-titled fifth studio album by the American heavy metal band Metallica. Released on August 12, 1991, it marked a significant shift in the band's sound, incorporating more mainstream rock elements. The album features hit singles like "Enter Sandman," "The Unforgiven," and "Nothing Else Matters," which contributed to its widespread popularity. The "Black Album" received critical acclaim and commercial success, selling over 16 million copies in the United States alone. It is often regarded as one of the greatest heavy metal albums of all time, solidifying Metallica's status in the music industry and influencing countless artists.