Bob Rock produced Metallica’s 1991 self-titled album.
The record was Metallica's first studio album made with Rock, who was already known for producing successful hard-rock recordings. James Hetfield, Lars Ulrich, and Rock are all credited in the album's production information, while Rock's role was central to shaping the album's focused and radio-ready sound.
The collaboration initially created tension because Rock pushed the band to reconsider its recording habits and song arrangements. The sessions ultimately produced a cleaner, more direct style than the dense production associated with ...And Justice for All.
Rock continued working with Metallica on later projects, including Load, Reload, and Garage Inc. The Black Album therefore represents not only a major commercial breakthrough but also the beginning of a long producer-band partnership.