Well according to Josh's biographer , Elijah Wald, Josh's family were impoverished by some peevish act of Jim Crow skulduggery.

So from the age of seven Josh had the job of leading round various blind singer guitarists - Jefferson being the most famous. They were all mean abusive characters, who kept nearly all the money and boozed and gambled it. They kept Josh barefoot even in the winter to make the act look more piteous. They were careful not to share their musical secrets - but I think - if we look carefully , we can see some of what he learned by observing. it was a tough apprenticeship.

From Jefferson himself. I would estimate the main technique he took was his way with bass staccato runs that are not just show pieces - they swing fiercely and drive the song along. With jefferson he added a sort of falsetto - Josh's voice is rich baritone but it weaves into these bass runs.

Josh doesn't go for the syncopated double finger picking. but he has ways of scooping and strumming at the strings that come at the listener as bewilderingly complex - making train noises, or bouncing a lyric at you. as people have pointed out Odetta used this kind of masterful strumming also.

The other thing that strikes me about Josh's work is the presentation. He is always telling you the story - trying to make you understand it, trying to draw you in. there is none of that celtic reverie business. he is in your face with interesting or amusing detail. his genius is taking the street corner shtick and making something that will work in the Gate of Horn or The Blue Angel, or down the lens of a tv camera. He must have worked hard at his diction to effect that translation.

There is also some quite exotic chording that gives an air of finesse.
These are my observations and I 'm sure there may be people who think I've got it wrong. Please put me right where i am wrong. This subject fascinates me..