At which Los Angeles studio did recording for Metallica's The Black Album primarily take place?

Recording for Metallica's The Black Album primarily took place at One on One Recording Studios in Los Angeles. The sessions began there in October 1990 and formed the core of the album's production.

The band also spent about a week at Little Mountain Sound Studios in Vancouver, British Columbia. Final overdubs and mixing were completed during four weeks at A&M Studios in Hollywood in June and July 1991. These additional locations sometimes lead to the mistaken belief that the album was recorded entirely at one studio.

One on One was central to the long and demanding process. The recording period lasted from October 6, 1990, to June 16, 1991, and involved repeated takes, collaborative performances, overdubbing, and detailed mixing.

Producer Bob Rock encouraged the musicians to record more as a unit and to capture a stronger live feel. The finished album's polished heaviness reflected both the Los Angeles sessions and the work completed at the other studios.