With prog metal, it's so difficult to determine when prog transcended rock n roll or hard rock, into the realm that we consider metal. And to think about it, either Dream Theater or Queensryche were the first to truly metallize prog. Did I just type 'metallize'? But I can't really think of a better example of when prog was wholly infused with a completely metal signature like these bands did.
For the transformation of hard rock to metal, it'd have to be Deep Purple. Simply listening to Highway Star, you can tell most obviously. The big thing is the keyboards. The Hammond sounds give that distorted, ripping, driven sound alongside the guitars in the time when guitars didn't really have super-duper amplifiers with bucketloads of gain to get that palm-muted, down-stroked crunch that really distinguishes metal. And the guitar solo of that song is where every following band realised that blending classical Bach-style chord progressions and faster patterns could sound so good on an electric guitar. You look at Angra, Edguy, Helloween, Symphony X, Randy Rhoads, Vai, Petrucci, MetallicA, any metal band... they all take that epic, sweeping, climbing, machinegun fast guitar playing from Ritchie Blackmore. No, they didn't have superfast, endurance double bass drumming just yet, cuz drummers back then didn't recognise how badass it was to have both feet pounding away. But Ian Gillian created the yardstick by which all singers measure themselves. Who here sings? Who here has tried to sing "Smoke on the Water" higher and louder and more blasting just to see how strong their voice stands next to Gillian's? *raises hand* Ever heard the cover of that song by Metalium? That's a perfect example. You can tell, even without adding the now-popular power metal signatures and styles, that old DP was so powerful and so impressive! So for one band to sit as King, it'll have to be Deep Purple for me. I saw them when they toured with Dream Theater, oh, maybe 6 years ago or so? And boy oh boy, did I understand it. It was then that I could tell where every modern power metal band gets their roots from. The flamboyant, in-your-face, rip roaring ambience that you need to kick an audience's ass. It was their presence! You felt them there! And every good power metal band has that ability to get on stage and make you feel it. And I'm not just talking about the concussion pounding you from the speaker towers when Blind Guardian rips through Valhalla!
Then after Deep Purple, the next incarnation would have to be Blackmore tag-teaming with Dio. Lyrically, Dio showed us all how a fantastic, imagination driven song can whup all kinds of ass with the right words to sing along with. Yeah, Deep Purple had some kickass themes, but it wasn't cool yet to sing about dragons and wizards and the evils of the night. Dio made it cool, and then some! You don't need to write songs about falling in love and broken hearts, you need to write songs about kickin ass! Long Liiiiiiive Rock n Rooooll! That's what I'm talkin about! And his solo career spawned great anthems that every band afterwards has probably played as they sat in a garage and jammed songs to figure out who they were. They weren't Lionel Ritchie, they weren't Elton John, they weren't John Lennon, they were METAL!
I have to give Dio the crown as the single most influentially METAL guy around. He fuckin invented the devil's horns!
As for the modern speed metal influences, then it has to go to Iron Maiden next. We'll call Maiden the Princes of Power Metal under the mighty King Dio. Bruce Bruce is what all new-age singers must compete with to prove their worth. You wanna be metal? You gotta "SCREAM FOR ME BRASIL!" Bruce proved that it took a MAN to scream like a woman!!! And the sound of two guitars belting out two-part melodies with intertwining harmonies, that's all about Murray and Smith. Right there. When my band's in the attic writing songs, and Roger and Kevin come up with a part and the other matches it with a harmony, we always go "Yeah, dude, that's Maiden! That's so Maiden! Keep that!" And besides.... you can always tell if a band truly has spent their time in the woodshed and learned their instrument, when they play a crap dive club, and bust out Maiden. I've seen hardcore bands and death metal bands galore, and every crap untalented never-gonna-go-anywhere opening up a show. And the ones that actually stand out, are the ones that can bust out Maiden in full force. Who was that... I think, they were called Pownd... these guys had the crowd going pretty well. True growler vocals. Didn't impress me with their playing, but that style doesn't require that. But when they played The Trooper, you could instantly tell the members of the band knew their roots! They spent their time shedding their guitars! And besides. What band can kick the asses of 100,000+ people in Rio De Janero, twenty years later? I dunno of that many old fogies who can draw that big of an audience today. I know we're gonna have a bouncing between Helloween and Maiden, cuz they're pretty much the same timeline, and certainly the same influence on the genre. But I still think that Maiden is a stronger force to contend with when the chips are on the table.
I will quickly give credit where it's due. Rob Halford is the most inventive and original of all singers. His voice is still copied and imitated and referred to. His screaming is what many many MANY power metal bands have sought after in a frontman, and still do today. You can't have a power metal band with a pussy voice in front there. You need a screeching demon to launch the assault!
Shit.. I turned this little quick response into a fuckin article for Metal Edge.
So...
GODFATHER OF HEAVY METAL: Tony Iommi
Grandfathers of Power Metal: Deep Purple
High King of Power Metal: Ronnie James Dio
Crown Princes of modern Power Metal: Iron Maiden
Banshee Lord of Power Metal: Rob Halford