And the Son House (Robert's old mentor) tune "Walking Blues." Robert's "Malted Milk" is a virtual Lonnie Johnson clone tune. His "They're Red Hot" was in a style simplified but very similar to one used in the late '20s by Blind Blake. In "Hellhound" he was obviously trying to imitate the very dark-blues sound of Skip James' earlier recordings and came very close, using the open-D DADF#AD tuning he was familiar with. But Skip actually used Open-Dm DADFAD which at that time was an extremely obscure tuning, used only by a few musicians who came from the Bentonia, Mississippi area. (That region was more mountainous and remote than the Delta region of Mississippi and had several very specific regional styles, including the use of open-minors and a pretty unusual fife-and-drum style of blues, much more African-sounding.) Robert wasn't yet a sophisticated enough guitarist to copy Skip's tuning, but he was good enough to create a tremendous tune with very close to the same sort of feel using his own methods. It seemed like Robert was trying to draw on the styles of several of the old-masters who had pre-dated him and incorporate it into his playing.
(As well as a bit of down-right plagerism! .... "... mmmm... babe... don'cha wanna go? Better pack yo' little suitcase... we're off to Sweet Home Kokomo"... )
People have been ripping each other off musically for hundreds of years, I don't think RJ was the first guy to do it.
Neither were Led Zeppelin....