Metallica: James Hetfield (vocals, guitar); Kirk Hammett (guitar); Jason Newstead (bass); Lars Ulrich (drums). Recorded at One On One Recording, Los Angeles, California between October 1990 and June 1991. When a genre-defining group like Metallica, whose past albums have rocked the charts with virtually no airplay, enlists the aid of a hit-making producer like Bob Rock, the result is bound to be monumental. METALLICA, their sixth studio release, surpasses all expectations. METALLICA is an extremely heavy album. It carries a presence, a huge, live sound different from that heard on their previous recordings. What once could not be tamed has been refined, resulting in a fuller, more powerful guitar sound in an already guitar-intensive band. They have evolved from the messy, unabashed thrashers of their youth into a more confident, poised and angry bunch, not only retaining their fire but stoking it into a chunky, tight-fisted maelstrom of scowling energy. Serious riffs provide punch and punctuation for James Hetfield's gruff vocals which rage against society and religion, and revel in suspicion and sarcasm. METALLICA is full of songs just as potent as the hugely popular "Enter Sandman," yet is not as complicated as their recent albums have seemed. "Sad But True," which is just as low down and dirty as anything labeled "grunge," exemplifies the poise of the metal band that can foresee the punchlines to their riffs and has the patience to wait for them.