Led Zeppelin played rock music.
Heavy metal ( or simply metal ) is a genre of rock music that developed in the late 1960s and early 1970s , largely in the United Kingdom and the United States . Led Zeppelin were an English rock band formed in London in 1968 . Rolling Stone magazine described them as `` the heaviest band of all time '' , `` the biggest band of the Seventies '' , and `` unquestionably one of the most enduring bands in rock history '' .