Sludge metal is a heavy subgenre associated with New Orleans and characterized by slow, heavily distorted riffs, abrasive vocals, and a deliberately raw sound. It combines elements of doom metal, hardcore punk, and southern rock.
The style developed during the 1980s and early 1990s through bands such as Eyehategod and Crowbar. New Orleans's humid atmosphere, underground music community, and connection to both punk and heavy rock helped shape the genre's distinctive sound.
Sludge metal is sometimes confused with stoner metal because both can use thick guitar tones and slow tempos. Sludge generally emphasizes harsher vocals, punk aggression, and a rougher production style, while stoner metal often draws more strongly from psychedelic rock.