Metallica is an American heavy metal band from Los Angeles, California, whose releases include fast tempos, instrumentals, and aggressive musicianship that placed them as one of the founding "big four" of thrash metal alongside Slayer, Megadeth, and Anthrax.[1] They formed in 1981 when James Hetfield responded to an advertisement that drummer Lars Ulrich had posted in a local newspaper. As of 2003, the line-up features long-time lead guitarist Kirk Hammett (who joined the band in 1983) and bassist Robert Trujillo (a member since 2003) alongside Hetfield and Ulrich. Previous members of the band are lead guitarist Dave Mustaine (who went on to found the band Megadeth), and bassists Ron McGovney, Cliff Burton and Jason Newsted.