I was watching a British TV show and they had a few moments about their Folk Music. Other than the different accents, it sounded much the same as what we call American Folk Music. So it does trace back many generations.
They stayed fairly true to the original. Then they jammed. I tried to include something from Sister Rosetta Tharpe, but somebody wasn't happy with the idea of doing it outside the Youtube web site. She is more Gospel than Blues, but has been cited for influencing music across multiple genres. Down by the Riverside
The Dead came from blues and country roots, they were at their best before "Pigpen", the original organ-keyboard-vocalist ,died around '72, at 27 (same time as Janis, his drinking buddy and occasional love interest...so that explains some things)
I tried to really get into The Dead, but the best that I could do was be okay with them. Your activity in this thread shows your range/versatility on topics. You are comfortable posting about Creed. Limp Bizkit, Nickleback etc and also music from before you were even born. A while back we had the Sugar songs and you pulled some early 70's Guess Who.