Led Zeppelin were a group.
Led Zeppelin . They are one of the best-selling music artists in the history of audio recording ; various sources estimate the group 's record sales at 200 to 300 million units worldwide . 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 '' .