Metallica is the self-titled fifth studio album by American heavy metal band Metallica. Released on August 12, 1991, by Elektra Records, it is commonly referred to as The Black Album because of its packaging design. Its recording took place at One on One Studios in Los Angeles over an eight-month span that frequently found Metallica at odds with their new producer Bob Rock. The album marked a change in the band's music from the thrash metal style of their previous four albums to a slower, heavier, and more refined sound.