Ok it's a little off topic, but if you love the blues how can you not be fascinated with this? I am. Clapton admires Johnson and describes the difficulty of what he was doing. The note-for-note versus approximation commentary would apply to those of us trying to learn harp by copying the great harp players as well, methinks.
Thanks for that post. There were so many VIPs in the audience (the Clintons, DeNiro, Kevin Spacey, Sheryl Crow) I had to go to YT to check out what this show was. Apparently, The Concert of The Century in Washington DC back in 1999. Of course the vid went directly into my favorites.