It's called "Things Ain't What They Used To Be". It's an Ellington tune. Duke used it to close a lot of his concerts. He did a finger-snapping bit with it. Great swinging tune.
No, after No Woman No Cry, he plays some blues. I heard that song, and even played it in a big band, it's well known jazz standard, but I can't remember the name...
I was 21 and one of the rare blessed to discover Monty at the unbelievable
Montreux Alexander Concert in 1976. Not to forget Jeff Hamilton and John
Clayton, fantastic musician too. What a revelation and still so beautiful,
40 years later. (I still have the vinyl).