Actually, we're not calling Power Metal the same thing. It's gonna be easier with examples
Speed Metal is a kind of extreme and faster Heavy Metal :
SACRED STEEL -
http://www.youtube.com/watch?v=N0UkFuajIww
AGENT STEEL -
http://www.youtube.com/watch?v=RWkUxl8V4uY
ADX -
http://www.a-d-x.ch/adv.wmv
Thrash Metal is not as fast and it no longer has high-pitched vocals :
SLAYER -
http://www.youtube.com/watch?v=CUDWLp1yIWw
TESTAMENT -
http://www.youtube.com/watch?v=E48UihPXujM
SODOM -
http://www.youtube.com/watch?v=v8rXeyph6wM
It's sometimes difficult to make a difference between Speed Metal and Thrash Metal.
HELLOWEEN were playing Speed Metal in the very beginning :
HELLOWEEN "Judas" (1985) -
http://www.youtube.com/watch?v=5r-rzBPYTC0
But then, they re-integrated the very melodic side of Heavy Metal and decided to use clear singing only. It turned out to be called Heavy Speed (Speed Metal with a Heavy Metal influence) :
HELLOWEEN "Eagle Fly Free" (1987) -
http://www.youtube.com/watch?v=BbFoUGkET-0
Same thing for BLIND GUARDIAN which were Speed Metal on their first album :
BLIND GUARDIAN "Majesty" (198

- http://www.blind-guardian.cz/archiv/BLIND%20GUARDIAN%20-%20(sample)%20Majesty.mp3
Much more melodic and not as aggressive a few albums later, thus Heavy Metal oriented. That is Heavy Speed :
BLIND GUARDIAN "Mirror Mirror" (199

- http://www.blind-guardian.cz/archiv/BLIND%20GUARDIAN%20-%20(sample)%20Mirror%20Mirror.mp3
Power Metal sounds like that :
PANTERA -
http://www.youtube.com/watch?v=Km8xIs24UeY
MACHINE HEAD -
http://www.youtube.com/watch?v=UNyzZQZHYs8
DEARLY BEHEADED -
http://www.youtube.com/watch?v=j3N513Eb1ko
To me, bands like EDGUY, DRAGONFORCE, GAMMA RAY, etc. sound much more like HELLOWEEN's "Eagle Fly Free" than PANTERA's "I'm Broken", don't they ? You call Power Metal what we've been calling Heavy Speed for almost 20 years now in Europe, as far as I know.
You can have a look to this diagramm
http://membres.lycos.fr/ericlestrade...diagramme2.gif that tries to gather all Metal styles. I disagree on certain points (their so-called "European Power Metal" has nothing to do at all with their "US Power Metal" for instance--so why the fuck do they give them the same name ??) but it's pretty good on the whole though.
PS: That's just what I think, you may disagree of course
