Thrash Metal

Thrash metal is possibly the most popular subgenre of metal among metalheads. Basically, it's a fusion of Hardcore Punk and the music of the New Wave of British Heavy Metal (NWOBHM; you know, Iron Maiden). In slightly more detail, thrash metal, also known as "thrash", features very fast guitar playing, often with a signature "chugging" sound, and very fast drumming. Seriously, the drumming is impossibly fast... unless you're an actual thrash metal drummer, in which case, it's not.

Thrash metal began in the early eighties, and was popularized mainly by the "Big Four" (Metallica, Megadeth, Slayer and Anthrax) as well as the three main bands of the Teutonic thrash metal scene in Germany (Sodom, Kreator, Destruction). Nowadays it's a bit old-fashioned, but still sufficiently popular that it has seen a "revival" of sorts in the 2000s (see the "New Blood" section). In June of 2010, the Big Four of thrash metal played together on one stage for the first time ever in a historic concert tour in Europe.

Fellow metal genres Death Metal, Groove Metal and arguably Black Metal evolved directly from thrash. Thrash metal evolved from Speed Metal, and was instrumental in the creation of Power Metal

Bands typically described as thrash metal include:

Old Guard

American West Coast
 * Dark Angel
 * Death Angel
 * Exodus
 * Forbidden
 * Heathen
 * Hirax
 * Lääz Rockit
 * Megadeth
 * Metallica
 * Sadus
 * Slayer
 * Testament
 * Tourniquet (also Progressive Metal and Christian Metal)
 * Torture
 * Vio-lence

American East Coast
 * Anthrax
 * Carnivore
 * D.R.I (later)
 * Demolition Hammer
 * Hallows Eve
 * Iced Earth (later became Power Metal)
 * M.O.D
 * Nuclear Assault
 * Overkill
 * S.O.D
 * Toxik (also Progressive Metal)
 * Whiplash
 * Watchtower (also Progressive Metal)

Misc. American
 * Exhorder (Mixed with Groove Metal)

Teutonic (German)
 * Assassin
 * Angel Dust (later became Power Metal)
 * Destruction
 * Despair
 * Exumer
 * Holy Moses
 * Kreator
 * Living Death
 * Mekong Delta
 * Paradox, beginning with Heresy (formerly Speed Metal)
 * Protector
 * SDI
 * Sodom
 * Tankard
 * Violent Force

Brazilian
 * Attomica
 * Dorsal Atlantica
 * Executer
 * Explicit Hate
 * Holocausto
 * Korzus
 * Mutilator
 * MX
 * Sarcófago (Mixed with Black Metal and Death Metal)
 * Sepultura before Chaos AD (later became Groove Metal; they brought back the thrash/death influence starting with Dante XXI)
 * Soulfly, beginning with Dark Ages

Canadian
 * 3 Inches of Blood (also Power Metal)
 * Annihilator (fused with Speed Metal and Progressive Metal; later material mixed with Groove Metal as well)
 * Anvil (YMMV, has more in common with Heavy Metal with Power Metal touches)
 * Infernäl Mäjesty
 * Razor
 * Sacrifice
 * Voivod (also Progressive Metal)

Misc.
 * Hobbs Angel Of Death (Australian)
 * Mortal Sin (Australian)
 * Sabbat (British)
 * Onslaught (British)
 * Coroner (Swiss)

New Blood
 * Barbatos
 * Bodycount
 * Bonded By Blood
 * Demiricous
 * Diamond Plate
 * Evile
 * Fueled By Fire
 * Gama Bomb
 * God Forbid
 * Havok
 * The Haunted
 * Hexen
 * Lazarus AD
 * Lich King
 * Machine Head, beginning with The Blackening (formerly Groove Metal)
 * Mantic Ritual
 * Merciless Death
 * Municipal Waste
 * Razormaze
 * Revocation
 * The Showdown (recent material, Started out somewhere in between Death Metal and Metalcore)
 * Susperia
 * Toxic Holocaust
 * Vektor
 * Warbringer

Tropes common in this genre are:

 * Darker and Edgier: Compared to its direct progenitor Speed Metal.
 * Gorn: Not used as much as death metal, but still occasionally used, most famously by Slayer.
 * Harsh Vocals: occasionally employed, doing it to much leads to confusion with Death Metal.
 * Metal Scream: Often more of the operatic or snarling variety.
 * Mohs Scale of Rock and Metal Hardness: Generally ranges from 8-10 (ten being more rare).