in 1990, rock was chosen to produce metallica's diamond-certified (16x platinum) self-titled album (commonly referred to as "the black album"). he subsequently produced "load" (1996) and "reload" (1997) as well as the new material for the band's cover album "garage inc." (1998). after jason newsted left metallica in january 2001, rock wrote and recorded all of the bass guitar parts on the 2003 album "st. anger". he played bass during the band's few live performances until robert trujillo joined the band in february 2003. rock was featured prominently in the 2004 documentary film "". the film dealt with metallica's internal strife and their struggles with the creative process during the recording of "st. anger".