Knowing all of your appreciation for great old school, wanted to send you this link. There was a PBS show in the late 60s/early 70s called "Soul" that aired on WNET New York.
Anyway, they made 40 episodes of the show over the period of 1968 to 1973, so you can just imagine the treasure trove of performances. I'd heard of it, but had never gotten to see any.
They just put 6 episdoes on line, they plan to get all 40 up at some point. The ones they have include EW&F, Ashford and SImpson, the Persuasions, Max Roach and more. If you look at the program listing for all the eps, you can see what's coming when they get the rest on line.
This is some amazing stuff that hasn't been seen in years: