Having already established themselves as the streetwise saviors of heavy metal's oft-tainted legacy in the '80s, Metallica rebounded from the accidental death of original bassist Cliff Burton to produce their most thematically challenging, musically accomplished album to date. Despite James Hetfield's dank, extended portraits of a world collapsing from corruption and decadence - themes that virtually guaranteed it little radio or television exposure - the album was nonetheless a muscular commercial success. Even One, its complex, seven-and-a-half-minute adaptation of Dalton Trumbo's Johnny Got His Gun, managed to scale the singles charts. Other highlights include Blackened, Eye of the Beholder, and the sweeping To Live Is to Die, tracks that underscore a sense of musical ambition that's often downright prog-centric, yet never merely self-indulgent.