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.
Argentine heavy metal
The Argentine heavy metal is a heavy metal music movement that originated in Argentina in the 1980s. The first popular artist was Pappo, who created the band Riff influenced by the contemporary new wave of British heavy metal. V8 was formed at that time as well, and most of its members created notable bands after their respective departures from the band: Ricardo Iorio and Walter Giardino, currently in Almafuerte and Rata Blanca, are still popular. The second half of the 1980s saw the success of hard rock bands such as Kamikaze, Alakran and Rata Blanca, with an aesthetic similar to the contemporary glam metal. Thrash metal bands, such as Hermética, Horcas and Lethal, appeared in the early 1990s.