Metallica is an American thrash-metal band founded in 1981 in Los Angeles. For the first Metallica album is characterized by a faster tempo songs, and his aggressive style and musically challenging compositions. This is included together with bands Megadeth, Slayer and Anthrax in the “Big Four” thrash metal. The group put together by an ad in the Los Angeles newspaper, which gave drummer Lars Ulrich. The group plays a lead guitarist Kirk Hammett (who joined the group in 1983), bassist Robert Trujillo (member since 2003) along with founding drummer Lars Ulrich and the singer and rhythm guitarist James Hetfield.