This, to me, is the coolest riff Page ever put down on guitar. Is it a traditional blues progression? Sure, but the way Page combines this acoustic riff with electric guitar and turns it into a blues rock masterpiece still astounds me today. He was a little over twenty when he recorded this. The swagger of this song is still unmatched in my opinion. You can bring up Beck, Clapton, Richards, Townsend, or Steve Vai, but none of them put anything down that sounded as confident and cool as this song.