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.
Japanese metal
The decade is seeing a , with a large number of all-female heavy metal bands forming and gaining mainstream attention. Although not the first to form, Aldious have been cited as the initiators of the movement when their debut album "Deep Exceed" (2010) topped the Oricon Indies Albums Chart and reached number 15 on the main chart. Another notable girls metal band is Cyntia, who are believed to have been the first of the movement to join a major record label when they signed to Victor Entertainment in 2013.