Metallica were easily the best, most influential heavy metal band of the '80s. Responsible for bringing the genre back to Earth, the bandmates looked and talked like they were from the street, shunning the usual rock star games of metal musicians during the early '80s. Metallica also expanded the limits of thrash, using speed and volume not for their own sake, but to enhance their intricately structured compositions. The release of 1983's Kill 'Em All marked the beginning of the legitimization of heavy metal's underground, bringing new complexity and depth to thrash metal. With each album, the band's playing and writing improved; James Hetfield developed a signature rhythm playing that matched his growl, while lead guitarist Kirk Hammett became one of the most copied guitarists in metal. To complete the package, Lars Ulrich's thunderous (yet complex) drumming clicked in perfectly with Cliff Burton's innovative bass playing.