c. 1960 -- (from the 'coke' [Coca-Cola] section, being under 21) Duke Ellington and his Orchestra at Storyville, Boston. I asked him where his guitar player was. He looked a little surprised and said he hadn't carried one in several years -- I had momentarily confused his personnel with Basie and was looking for Freddie Green. I'd felt like an idiot, but I'm glad I can say I spoke with him once.
c. 1963 -- Clarence and Roland White playing with the Kentucky Colonels in Los Angeles. (The era of the Clarence vs. Doc arguments.)
c. 1964 -- Bill Monroe and George Jones jamming backstage at Madison Square Garden. George was feeling no pain and belted out bluegrass songs while simultaneously mocking the bluegrass guitar style -- only he could get away with that in Monroe's presence.
many times, '60s -- Doc Watson with Tom 'Clarence' Ashley and Co.
many times, '60s -- Butterfield Blues Band with Mike Bloomfield, Elvin Bishop, Jerome, and Sam Lay.
1968 -- The Count Basie Orchestra in a relatively intimate setting (my dad's 25th college reunion). I asked him if they still did various old tunes. After 2 or 3 'no's, I mentioned "Moten Swing", one of the oldest, which they promptly played.
many times, '80s -- The Neville Brothers.
Well, this has been fun -- for me. Not sure how it enlightens anyone else.