Megadeth is an American heavy metal band formed in Los Angeles in 1983 by vocalist and guitarist Dave Mustaine. Known for their technically complex guitar work and musicianship, Megadeth is one of the "big four" of American thrash metal—along with Slayer, Anthrax, and Metallica—and is credited with helping to develop and popularize the genre. Their music features intricate arrangements, fast rhythm sections, dual lead guitars, and lyrical themes such as war, conflicts, politics, religion, death, and personal relationships.