Thrash,,

Thrash was essentially the sound of underground heavy metal during the '80s, dominated by a driving, percussive approach to rhythm guitar (thanks to a pick-hand technique called palm muting) and furious levels of aggression. Thrash was often technically accomplished, taken at fast tempos, and emphasized heavy, sometimes atonal guitar riffs over melody; however, these generalizations are far from absolute rules. In its early days, thrash was essentially the same thing as speed metal, the product of American bands who in the early '80s fused the lean, vicious attack of the New Wave of British Heavy Metal with the tempos of hardcore punk and Motorhead. However, the dexterity and constant intensity required to play speed metal proved limiting to some, and a variety of different approaches quickly took shape: some thrash bands concentrated more on midtempo grooves, occasionally accelerating into speed-metal realms; some, like Metallica and Megadeth, used their instrumental technique to craft more intricate and progressive music; others emphasized the music's aggression to project theatrically menacing images. Thrash provided a harder, heavier, more authentically metallic alternative to the accessible pop-metal bands who dominated the charts in the late '80s, and despite a dearth of airplay, it became quite popular, so much so that when Metallica and Megadeth streamlined their sound to make it more accessible in the early '90s, they became instant superstars. Diehard underground metalheads took refuge in the thrash-inspired death and black metal styles, which took thrash's dark subject matter and visceral force to intentionally disturbing extremes.