GASP! "Paul Gilbert" = RacerX
Well, you have to put the timeframe into perspective.
When Street Lethal came out in the mid/late 80's (Gilbert was 18 or 19), that dropped a lot of jaws. Most stuff was just "Metal" (excepting "Thrash", which Powermetal isn't). Even the thrashers had big hair.
The only things that were faster/intense was thrash, and Anthrax, Metallica, etc had a pretty distinctly different sound. Helloween was around then, too!
As mentioned in my last post Road Runner Records and the Mike Varney showcases (Shrapnel Records) WERE the template for "power metal" (and later Metal Blade records).
It was those shredders that brought in the 'neo-classical' influence and that 'epic' power metal sound, like Yngwie Malmsteen (epic keys, epic vocalists screaming about dragons and shit). In fact, I'll go so far as to say if you trace back that sound, it stops at Yngwie Malmsteen.
Absolutely NOTHING sounds wholesale like this before this stuff-- we take this sound for granted today, but this level of shredding and epic keyboard tradeoffs with the fast double bass just wasn't around en masse.
There was 'fast' and 'fast and heavy' but not this template sound (heavy influences like Deep Purple, Iron Maiden, Motorhead, etc):
Another early powermetal band (Vinnie Moore's old band):