I was one of those fortunate enough to have attended most of these shows from '63 onward, still have some of the posters a large number of photographs and many great memories.
Just a small point from the article above which includes Champion Jack Dupree in the 'cast' list. I am pretty sure that Jack wasn't on any of these shows. He first came to the UK in either 58 or 59, I still have a radio broadcast which he did in 1959 for the BBC. He actually took up residence in Yorkshire for a number of years and regularly toured the clubs here and elsewhere in Europe.

For blues minutiae freaks can I say that I and a couple of work colleagues brought two of theses musicians to the UK to make their European debut before they appeared on these festivals; Little Walter in 1964 and Buddy Guy in 1965.

Great days, great music.