At which primary recording studio did Metallica record the 1991 album commonly called The Black Album?

Metallica recorded its 1991 album, commonly called The Black Album, primarily at One on One Recording Studios.

The studio was in Los Angeles, California, and the main sessions began there in October 1990. The recording period lasted roughly eight months, reflecting the band's perfectionism and the demanding collaboration with producer Bob Rock. The band also spent about a week at Little Mountain Sound Studios in Vancouver, British Columbia.

Final overdubs and mixing took place at A&M Studios in Hollywood during June and July 1991. That distinction matters: One on One was the principal recording location, but it was not the only studio connected with the finished album.

The sessions were also notable for a different working method. James Hetfield wanted the group to create more of a live feel, so Rock encouraged the musicians to record collaboratively. The album's drums were retained while guitars, bass, and vocals were overdubbed afterward, helping create its large, controlled sound.