At which Los Angeles studio did Metallica primarily record its 1991 album Metallica?

Metallica primarily recorded its 1991 album Metallica at One on One Recording Studios in Los Angeles.

The main recording period ran from October 6, 1990, to June 16, 1991. The band also worked for about a week at Little Mountain Sound Studios in Vancouver, British Columbia, and completed final overdubs and mixing at A&M Studios in Hollywood.

One on One was therefore the principal studio associated with the album, but it was not the only location used. This distinction matters because album summaries sometimes list every studio together, while fans may remember only the Los Angeles facility where most of the sessions occurred.

The production process was unusually demanding. Producer Bob Rock encouraged the members to record more collaboratively and insisted on repeated takes to capture the desired feel. The lengthy sessions and frequent disagreements were later shown in the documentary A Year and a Half in the Life of Metallica.