I learned the folky country tune “Big River Blues” from Doc Watson. Somewhere or other he mentioned he learned the song from the Delmore Brothers, and yesterday I came across that original version.
Here it is: Big River Blues (mp3)
This recording is from the 1930s. The genre is self-aware as something like country and western, probably with an emphasis on the western. Their conception of the style is that it’s slightly slick rube music, more in tune and less liquored up than the crude early days only ten years before. The single-note lead guitar line might be on an early electric instrument. It a step on the evolutionary path to rockabilly, and you can start to hear how something like Carl Perkins would come out of this.
Their guitar lead got picked up in Doc Watson’s version, modified to use his Merle Travis influenced picking technique rather than a flatpick. I didn’t grab that lead line when I learned the Doc stuff, it just didn’t catch my ear that strongly. And I used the title from Doc’s version; _Deep_ River Blues rather than _Big River Blues_.