Heavy metal music
Critics disagree over who can be thought of as the first heavy metal band. Most credit either Led Zeppelin or Black Sabbath, with American commentators tending to favour Led Zeppelin and British commentators tending to favour Black Sabbath, though many give equal credit to both. A few commentators—mainly American—argue for other groups including Iron Butterfly, Steppenwolf or Blue Cheer. Deep Purple, the third band in what is sometimes considered the "unholy trinity" of heavy metal (Black Sabbath, Led Zeppelin, and Deep Purple), despite being slightly older than Black Sabbath and Led Zeppelin, fluctuated between many rock styles until late 1969 when they took a heavy metal direction.
Black Sabbath (album)
In the opinion of the author and former "Metal Maniacs" magazine editor Jeff Wagner, "Black Sabbath" is the "generally accepted starting point" when heavy metal "became distinct from rock and roll". In his opinion, the album transfigured blues rock into "something uglier, found deeper gravity via mournful singing and a sinister rhythmic pulse". According to "Rolling Stone" magazine, "the album that arguably invented heavy metal was built on thunderous blues-rock". Sputnikmusic's Mike Stagno notes that Black Sabbath's combined elements of rock, jazz and blues, with heavy distortion created one of the most influential albums in the history of heavy metal. In retrospect, "Black Sabbath" has been lauded as perhaps the first true heavy metal album. It has also been credited as the first record in the stoner rock and goth genres.