In 1983, guitarist/vocalist Dave Mustaine formed the thrash metal quartet Megadeth. Though Megadeth followed the basic blueprint of Metallica's relentless attack, Mustaine's group distinguished themselves from his earlier band by lessening the progressive rock influences, adding an emphasis on instrumental skills, speeding the tempo up slightly, and making the instrumental attack harsher. By streamlining the classic thrash metal approach and making the music more threatening, as well as making the lyrics more nihilistic, Megadeth became one of the leading bands of the genre.