some styles of Metal (brief, brief overview...)
1.80's Power Metal- (falsetto vocals, dual harmonized guitars, pop sensibilities, etc...)
Include acts ranging from Iron Maiden, Motley Crue, early early Pantera, Extreme, Racer-X,etc
2.Thrash Metal- (fast tempo, emphasis on dissonance, technically proficient soloing, however generally lacking direction, very 'tinny' sound)
Include acts such as Slayer, Anhtrax, Megadeth, Exodus, early Kill Em All era Metallica, Motorhead, Judas Priest, 90's Pantera
3.Death Metal- generally popular throughout scandinavian countries, particularly Sweden- emphasis on songs about death and gloom, depressing lyrics...however, not directly to anti-christian/religious activity...more emphasis made on musicality in comparsion to thrash...
Include artists such as- At The Gates, Dark Tranquility, Death (only barely), Opeth, Arch Enemy (although they do borderline thrash)
4. Black Metal- Also popular within the scandinavian countries, however a use or keyboard, higher screeched vocals and direct links to anti religious sentiments inherent in their lyrics..include artist such as Emperor, Satryicon- particularly popular in Norway
5. Nu-Metal- Western/Anglo form of modern metal, incorporating the use of a dj, rapped vocals, samples, simple, downtuned guitar lines...Include artists such as Korn, Limp Bizkit, Linkin Park, Slipknot- often looked down upon by 'true metal fans'
6. Prog Metal- Style with a major emphasis on musicality with all instruments contributing extended soloing, musical progressions with major contrasts throughout their pieces
Include artists such as Dream Theater, Tool, Rhapsody, Symphony-X, Stratovarius, Cog
7. Goth Metal- Metal music associated with gothic contexts and culture...include artists like Cradle of Filth (barely)
8. Doom Metal- music associated with pessimistic undertones, gloomy contexts to the extremity...generally low tempos used, slow, groovy beats used...extended low growls include bands like My Dying Bride, Virgin Black
9. Pop Metal- acts like Poison, Van Halen, The Darkness, etc
check out
www.ultimatemetalforums.com for a more indepth analysis of the metal genre, feel free to add any more I have forgotten