Metallica is an American heavy metal band originally from Los Angeles, but based in San Francisco. Their repertoire includes fast, heavy, melodic, instrumental tempos and aggressive musicianship, which has placed them as pioneers of thrash metal and one of the founding bands of the Big Four of Thrash, along with Slayer, Megadeth and Anthrax. Metallica formed in 1981 after James Hetfield answered an ad that Lars Ulrich placed in the local newspaper. Their current lineup features founders Ulrich (drums) and Hetfield (vocals and base guitar), guitarist Kirk Hammett (who joined the band in 1983), and bassist Robert Trujillo (a member since 2003). Before reaching their current lineup, the band had other members, being: Dave Mustaine (guitar), Ron McGovney, Cliff Burton and Jason Newsted (bass).

With the release of their first four albums, Metallica gained a growing fan base in the underground music community, and some critics say that Master of Puppets (1986) is one of the most influential and “heavy” thrash metal albums. Soon after, the band achieved enormous commercial success with their 1991 self-titled album (also known as The Black Album), which has sold 40 million copies worldwide to date. With this release the band expanded their musical direction, reaching a more mainstream audience. With the releases of Load and Reload in the 1990s, Metallica tried to approach the alternative rock that was successful at the time to gain a new fan base, but was accused by their old fans of “selling out” to the record companies. In 2000 Metallica were among several artists who filed a lawsuit against Napster for sharing copyrighted materials freely without the band members’ consent. The settlement was reached, and Napster became a paid-use service.

Despite reaching number one on the Billboard 200, the 2003 release of St. Anger was controversial for its nu-metal influences and Bob Rock’s raw musical production. The successor album, Death Magnetic (2008), was produced by Rick Rubin and received more favourable reviews. Later, the ensemble’s studio discography added the album Lulu (2011), in partnership with Lou Reed and which received mixed reviews. In 2012, the band founded their own record label, called Blackened Recordings, and acquired the rights to all of their studio albums. Their most recent album is Hardwired…to Self-Destruct, released in late 2016. In their more than 30-year career, Metallica has released ten studio albums, four live albums, ten video albums, among others. They have become one of the most influential and successful bands of all time, having sold nearly 200 million records worldwide. The band has won nine Grammy Awards, entered the Rock and Roll Hall of Fame in 2009, and has six consecutive #1 albums on the Billboard 200.

Metallica fans are extremely devoted and faithful and while during the ’80s their main audience was composed of a vast male public (Thrashers), nowadays Metallica reached the heart of the general public, men and women.