Led Zeppelin III was, I think, the first album of theirs I ever owned. And now, sixteen years later, I’m just now noticing that the background guitar on the right-hand channel leading up to the chorus is going through an amp with a heavy tremelo effect.
I think Jason Boyles once suggested, based on more recent work (the Black Crowes live disc he appeared on), that Page was really not a great player live. I would dispute that–the DVD they released a couple of years ago has some great playing on it, and singlehandedly revived my interest on ??We’re Gonna Groove??–but it’s also beside the point: I think Jimmy Page was the first rock and roll guitar player to think in terms of orchestration of guitar.
Now, others followed on quickly–Robert Fripp debuted with King Crimson in ’69 (although even as a fan I would content that his guitar playing is distinctly un-rock-and-roll), Pete Townshend was starting to become more textured in how his guitar worked, Brian May would soon take the concept to its logical absurdity with Queen–but I don’t think it’s in any way inaccurate to say that Page started it.