Where were most of Metallica’s 1991 album recording sessions held?

Most of Metallica’s 1991 album recording sessions were held at One on One Recording Studios.

The studio was in Los Angeles, where the band recorded from October 1990 through June 1991. The album’s credits identify One on One as its principal studio, although additional work also took place elsewhere, including a short period at Little Mountain Sound Studios in Vancouver.

The sessions were unusually demanding for Metallica. Producer Bob Rock asked the musicians to play together more often, aiming for a stronger live feel. The band’s perfectionism led to many takes, extensive editing, and repeated mixing work before the final version was approved.

One on One is sometimes confused with A&M Studios, where additional overdubs and mixing occurred near the end of production. The primary recording location, however, was One on One in Los Angeles.