Metallica completed the final overdubs and mixing for The Black Album at A&M Studios in Hollywood.
Most of the album’s recording took place at One on One Recording Studios in Los Angeles, where the band began sessions in October 1990. The group also worked for about a week at Little Mountain Sound Studios in Vancouver. A&M Studios was the later-stage location used for final overdubs and mixing during June and July 1991.
These distinctions matter because several studios are connected with the record. One on One is the primary recording studio listed for the album, while A&M Studios handled the finishing work that prepared the performances for release. Mixing is the stage where recorded elements are balanced and shaped into the final stereo presentation.
The completed album was released by Elektra Records on August 12, 1991. Its finished sound represented a deliberate shift from the more aggressive thrash-metal character of Metallica’s earlier albums toward a slower, heavier, and more polished production style.