At which Los Angeles studio were most sessions for Metallica's The Black Album held?

Most sessions for Metallica's The Black Album were held at One on One Recording Studios in Los Angeles.

Metallica began recording there in October 1990, working with producer Bob Rock during sessions that lasted about eight months. The band also spent about a week at Little Mountain Sound Studios in Vancouver, while final overdubs and mixing took place at A&M Studios in Hollywood.

One on One therefore identifies the principal recording location, not the only studio connected with the album. This distinction matters because the record's production history includes several facilities and multiple stages of work.

The Los Angeles sessions were demanding. Rock encouraged the musicians to record more collaboratively and to capture a stronger live feel, changes that contributed to the album's tighter arrangements and heavier low end. The band and producer often disagreed, and the tension became part of the album's documented history.

The record was completed in time for its August 12, 1991 release through Elektra Records.