 The "vaguely medieval, minor-key sounds" of Rainbow, Dio and Judas Priest has also been described as "gothic" prior to "the emergence of goth rock as a post-punk genre".The bands Blue Öyster Cult and Iron Maiden have featured some gothic lyrics in their music on songs such as "(Don't Fear) The Reaper" and "Phantom of the Opera".Deep Purple's song "Stormbringer" has been called a "goth metal treasure".