At which Los Angeles studio was Metallica's The Black Album primarily recorded?

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

The main recording sessions began in October 1990 and occupied roughly eight months. One on One was the principal studio for the album, where the band worked with producer Bob Rock and engineer Randy Staub.

The project also involved other locations. Metallica spent about a week at Little Mountain Sound Studios in Vancouver, British Columbia, and later used A&M Studios in Hollywood for additional overdubs and mixing. Those extra locations do not replace One on One as the album's primary studio.

The long sessions reflected the band's perfectionism and Rock's insistence on capturing stronger, more unified performances. The recording period ended in 1991 before the album's August release.