Actually, the Greil Marcus book makes more sense after you have the Anthology disks and the two wonderful booklets that come with it.

(One is Harry Smith's original booklet, which, among other things, summarizes each ballad in a phrase like a newspaper headline; the other is the Folkways one, typically full of all sorts of documentation and essays about the anthology itself and what it meant to people when it first appeared...)

But after all that, you could dispense with Marcus and go to Dylan's autobiography, where he describes memorizing songs from CDs that he played over and over in the store, borrowing peoples CDs (often folkways, not always returning them) , browsing through the libraries and reading the books of the people whose New York sofas he stayed on.

He was voraciously hoovering up music and literature wherever he went, which makes the idea of a one LP source unlikely.