the release of pantera's cowboys from hell is considered the starting point of groove metal, a genre heavily inspired by thrash metal that places emphasis on heavy guitar riffs with usually syncopated rhythms (weird rhythms). guitars are generally down-tuned (the guitar sounds lower and heavier). vocals in groove metal usually rely on yelling, growling, screaming, or heavy raspy singing. groove metal is occasionally influenced by early, blues-inspired heavy metal bands such as black sabbath and deep purple.

• seminal groove metal bands:

pantera, machine head

• important groove metal album:

pantera - cowboys from hell (1990)