For anyone interested in music of substance, the metal scene of the
 early '80s was a pretty bleak place, dominated by cheesy hair bands
 hawking bubblegummy rock that had been dolled up with beefy guitars
 and naughty lyrics. Metallica, along with contemporaries like 
Megadeth and Anthrax had something altogether different in mind. 
Influenced by punk principles of raw musical directness and lyrical 
focus fraught with a dark and brooding idealism, they helped lay the 
groundwork for a whole new era of metal.

Metallica's many strengths were evident from the very beginning on
 their debut album Kill 'Em All. The scope, vehement playing, solid
 songwriting, and ambitious themes blended a stylized, almost Gothic
 sense of doom 'n' gloominess with an odd literary quirk (though it 
wasn't directly derrived from John Donne or Ernest Hemmingway, the
 cataclysmic mood of "For Whom The Bell Tolls" was something of a
 precursor to "One," ...And Justice For All's stunning rock adaptation
 of Dalton Trumbo's Johnny Got His Gun) and charged it all with the 
incensed energy of hardcore punk. Master Of Puppets was the culmination
 of the early half of their career, a prodigious display of speed metal
 and a pristine rock album. Their 1991 self-titled album was a 
watershed for many reasons. With it they refined and intensified their
 metal premise, but also made a statement about the power of the DIY 
ethic. Through relentless touring and uncompromising musicianship they
 had built an immense fan-base without the benefit of MTV, mainstream
 media coverage or radio support.