What was the primary recording studio for Metallica's The Black Album?

Metallica's The Black Album was recorded primarily at One on One Recording Studios in Los Angeles.

The recording period ran from October 6, 1990, to June 16, 1991, covering roughly eight months of work. The band also spent about a week at Little Mountain Sound Studios in Vancouver, while later overdubs and mixing took place at A&M Studios in Hollywood.

One on One was therefore the album's principal studio, not its only recording location. This distinction matters because several facilities contributed to the finished record.

The sessions became known for their demanding process. Metallica often recorded many takes, then selected and edited the strongest performances. Bob Rock's insistence on collaborative playing also changed how the band worked in the studio compared with earlier albums.