Groove Metal

Primary Stylistic Influences:

Thrash Metal, Traditional Heavy Metal, Blues Rock

Secondary Stylistic Influences:

Death Metal, Crossover Thrash, Hard Rock, Sludge Metal

Groove metal is, naturally, a subgenre of Heavy Metal. Considered either an evolution of Thrash Metal or a return to metal's blues-rock roots, groove metal is characterised by bluesy, slow-to-mid-tempo guitar riffs and Harsh Vocals. It's a very obscure genre name, but the bands from the genre are not.

Groove metal was most popular in the early nineties, after which it got replaced by Nu Metal, which itself occasinally took influences from Groove Metal (some bands more than others). Several Groove Metal bands have extensive Metalcore elements, a couple examples being Lamb of God and Shadows Fall. Groove Metal also tends to take elements from Death Metal, particularly Morbid Angel and Obituary.

Do not confuse the genre with Funk Metal, which is a sub-genre of Alternative Metal that focuses on bass playing and rhythm. The two genres, however, occasionally overlap, such as in the case of Soulfly. Due to its roots in Thrash Metal, groove metal is occasionally referred to as Post-Thrash. Also see Djent, a polyrythmic offshoot of groove metal.

Bands typically considered to be groove metal include:

4Arm (also thrash)
AxeWound
Brujeria
Byzantine
Cavalera Conspiracy
Chimaira (along with Metalcore, early material was nu metal)
Damageplan (formed from the ashes of Pantera)
Decapitated (as of Blood Mantra; mixed with Technical Death Metal)
Deftones (Usually considered Experimental or Alternative Metal, but starting with Diamond Eyes, this became a core part of their sound.)
Demon Hunter (also Alternative Metal and Metalcore)
The Devastated (also deathcore)
DevilDriver (also Melodic Death Metal)
Dharmata (Mixed with new metal and some vaguely deathcoreish riffs)
Dirge Within
Disciple (mainly their early material, but some of their later material still falls under the genre)
Divine Heresy (along with Metalcore, also has Deathcore elements here and there)

Down (one of Phil Anselmo's Many bands)
Dyscarnate (With All Their Might, also death metal)
DVSR (also Djent and Rap Metal)
Ektomorf (considered by many to be the Spiritual Successor to Sepultura)
Exhorder (usually considered the Trope Maker, but they were an aggressive, death metal-tinged thrash group on Slaughter in the Vatican and didn't assume a groovy sound until The Law, which hit the market around two years after Cowboys from Hell)
Fear Factory (mixed with Industrial Metal, Death Metal, Alternative Metal, Thrash Metal, and even a little bit of Nu Metal)
Fit For An Autopsy (Absolute Hope Absolute Hell, mixed with deathcore)
Five Finger Death Punch (Also Alternative Metal)
Forbidden (Distortion and Green, mixed with Progressive Metal)
Gloom (Genre-Busting example that mixes elements of this, death metal, black metal, sludge metal, and technical death metal, but this is probably the closest thing to an actual classifiable genre)
Gojira (also Death Metal, Technical Death Metal, Progressive Metal)
Grip Inc.
Hacktivist (primarily a combination of Djent and Hip-Hop, but the influence is felt)
Haji's Kitchen (also Progressive Metal, and Grunge for their early material)
Hatesphere (also some elements of Melodic Death Metal)
The Haunted (along with Melodic Death Metal)
Hellyeah
Lamb of God (death grind early on. Became groove metal since As the Palaces Burn)
Lazarus A.D. (mixed with Thrash Metal)
Machine Head (mixed with Thrash Metal, and with Nu Metal on a couple of their albums; became slightly more thrash than groove from The Blackening onwards)
Massacre (on Promise, which was....a bad move)
Meshuggah (also considered Djent)
Nonpoint (later)
Obituary (World Demise along with Death Metal, also extremely influential to the genre as a whole despite largely not being a full-fledged example)
Overkill (everything from I Hear Black to Immortalis, with thrash starting to creep back in circa Bloodletting)
Pantera (Trope Codifier or Trope Maker.)
A Perfect Murder
Pissing Razors
Powerman 5000 (also Industrial Metal)
Product of Hate
Pro-Pain
Prong (Also Industrial Metal)
The Resistance
Sepultura (from Chaos A.D. on)
- Roots (1996)
Shadows Fall (mixed with Thrash Metal and Metalcore)
The Showdown (recent material; mixed with Thrash and southern metal, with a distinct Death Metal bent)
Slipknot, (Subliminal Verses onward, though it was always an influence)
- 2014 - .5: The Gray Chapter
Soulfly (mixed with Nu Metal on the early albums, and Thrash Metal / Death Metal in their later albums)
Suicide Silence (between No Time to Bleed and You Can't Stop Me, also deathcore and nu metal)
Superjoint Ritual (another Phil Anselmo Project)
Testament (on Low and Demonic, mixed with and usually otherwise Thrash Metal)
Upon a Burning Body (also Deathcore and Nu Metal)
Westfield Massacre (also melodic metalcore)
Whitechapel (self-titled onward, along with deathcore; also started mixing in Nu Metal around that time as well)
White Zombie (La Sexorcisto onwards, mixed with Industrial Metal)

The groove metal genre contains the following tropes:

Careful with That Axe - It is fairly common in groove metal for vocalists to suddenly scream at random parts of a song. Pantera were rather well-known for making liberal use of the style, most notably in "The Great Southern Trendkill" (only with the help of Seth Putnam of Anal Cunt, however) and "Fucking Hostile".
Dead Unicorn Trope - Groove metal is a rather ill-defined genre; no one's really sure if it is a spin-off of thrash metal or a more "bluesy" variant of metal, or something entirely different. While musical characteristics such as slow-to-mid-tempo riffs, bluesy noodling, string bending and gravelly vocals are often used, there are so many exceptions that fans often argue about some bands that do not fall into the usual stereotypes.
Genre-Busting/Genre Roulette - Groove metal is fairly notable for the ease of fusing it with other heavy metal styles such as Progressive Metal, Power Metal, Thrash Metal, Death Metal and Nu Metal. Consequently, it has become common practice among groove metal bands to produce material that showcase seemingly disparate heavy metal stylings, as such with the case of Meshuggah (produced Technical Death Metal alongside their usual groove songs) and Nevermore (overlaps with Power Metal and Progressive Metal).
Genre Shift - Several bands have either shifted towards groove metal (Pantera, Sepultura, Fear Factory) or turned from groove metal to something else (Machine Head to nu-metal, though they eventually went back into groove metal).
Harsh Vocals - Grunts, rasps, and growls are very common in groove metal.
Mohs Scale of Rock and Metal Hardness - usually an 8 or 9, but a step up (e.g. Pantera — "Suicide Note Pt. II", a 10-11) or down (most of Hacktivist's stuff, a 6-7) on the scale isn't unheard of.
- The hardest bands in the genre are Lamb of God, Meshuggah, Fear Factory and Chimaira.
Soprano and Gravel - A few one-man variants, including Fear Factory and Machine Head.
Trope Codifier - If you regard Exhorder as the Trope Maker, then Pantera is probably the Trope Codifier. If you regard Pantera as a Trope Maker, then the Trope Codifier is open to debate, though Machine Head and Sepultura are the most likely candidates.
Trope Maker - Either Exhorder or Pantera. Or both.
Ur-Example - Pantera's Cowboys from Hell for groove metal in general.