Bob Rock was the first producer to produce a Metallica studio album, beginning with the band’s 1991 self-titled album, commonly called The Black Album. He co-produced it with James Hetfield and Lars Ulrich, who received assistant-production credits.
Metallica hired Rock after admiring his work on Mötley Crüe’s 1989 album Dr. Feelgood. His approach challenged the band’s established recording habits: instead of building tracks largely from separately recorded parts, he encouraged the members to perform more collaboratively and capture a stronger live feel.
The sessions were demanding. Recording took place mainly at One on One Recording Studios in Los Angeles over roughly eight months, and Rock frequently argued with the band about performances, lyrics, arrangements, and sound. The album was remixed multiple times before release.
The result was a major stylistic and commercial turning point. Metallica retained its heaviness but used slower tempos, more accessible structures, acoustic textures, and broader vocal expression. The album debuted at number one in ten countries and became the band’s best-selling release. Rock later produced Load, Reload, Garage Inc. material, and St. Anger, before Rick Rubin took over for Death Magnetic.