OK 6 is from a cd called "Duke Ellington, An Intimate Piano Session". It's one of the versions of Le Sucrier Velours done on August 25, 1972. (There are two takes and I haven't compared them to this yet.) I know about the session because a friend of mine told me he was present at an Ellington recording at which his brother was the engineer. He described it in detail and it didn't sound like anything I knew of. I contacted the brother, Jeff Lesser, who said it was never released but he remembered the studio and the approximate dates. After some research I was able to get the exact recording info and discovered that it was on a Duke Ellington Music Society tape that the late great Sjef Hoefsmit had sent out. With some difficulty I got a copy and made a digital version for Jeff and his brother. Shortly afterwards, of course, the cd appeared but it gives no credit to Jeff and in fact makes it sound like the engineer was the guy who I suspect engineered the "bonus tracks" which are from Rotterdam 1969.
I'm going on about this just to give some credit to Jeff Lesser. BTW Sjef's tape has even more "dialogue" than is found on the cd.
And Track 1 sounds like a live session by the Lincoln Center Jazz band, or someone of that ilk, with a guest pianist. (That's not meant to be a put down-- I've at times enjoyed them. )