Sludge metal

Sludge metal (also known as sludge doom or simply sludge) is an extreme subgenre of heavy metal music that combines elements of doom metal and hardcore punk. The genre generally includes slow tempos, down-tuned guitars and nihilistic lyrics discussing poverty, drug addiction and pollution.

The sound of sludge metal has its origins in California hardcore punk bands in the early-to-mid-1980s like Black Flag, Flipper and Fang, who began slowing their tempos and embracing the influence of Black Sabbath. This sound was expanded upon by the Melvins towards the end of the decade and the bands they influenced in both the Seattle grunge scene, and in Louisiana with Eyehategod, Crowbar and Acid Bath. In the 1990s and 2000s, the sound of sludge diversified: bands including Neurosis, Isis and Cult of Luna helped to pioneer post-metal, while Baroness and Mastodon fused the genre with progressive metal, while Dystopia did so with crust punk and Grief with anarcho-punk.

Characteristics

Alex Deller of Metal Hammer describes sludge metal as a "mutant cousin to both doom and stoner metal", incorporating the "misery of the former and the prodigious narcotic consumption of the latter while spewing nihilism, self loathing and frenzied punk rock aggression into the vomitous mix." He also described the style as "arguably the biggest, ugliest mutt" of the extreme metal subgenres.

The key characteristics of sludge metal are a slow tempo combined with down-tuned, heavily distorted guitars. However, some bands do make use of tempo changes into faster sections. The key element that differentiates sludge from other doom metal derived styles is its influence from hardcore punk, particularly the genre's use of high aggression and screamed vocals, though the genre can include sung vocals. Many sludge bands also make use of elements of industrial music, southern rock and blues.