Megadeth is an American heavy metal band established in 1983 by guitarist/vocalist Dave Mustaine and bassist David Ellefson, after Mustaine's departure from Metallica. They are noted for their technically complex guitar work and musicianship, characterized by aggressive, fast tempo, and intricate, neo-classical solos. Megadeth's significant contribution to the development of thrash metal, especially their albums "Peace Sells... but Who's Buying?" and "Rust in Peace," has given them a prominent place in heavy metal history. They are often mentioned as one of the "big four" of thrash metal, alongside Metallica, Anthrax, and Slayer.