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.
Heavy metal music
During the late 1980s, the power metal scene came together largely in reaction to the harshness of death and black metal. Though a relatively underground style in North America, it enjoys wide popularity in Europe, Japan, and South America. Power metal focuses on upbeat, epic melodies and themes that "appeal to the listener's sense of valor and loveliness". The prototype for the sound was established in the mid-to-late 1980s by Germany's Helloween, which combined the power riffs, melodic approach, and high-pitched, "clean" singing style of bands like Judas Priest and Iron Maiden with thrash's speed and energy, "crystalliz[ing] the sonic ingredients of what is now known as power metal".