This is the legendary R&B group The Temptations performing a long, 9-minute medley of songs from...Fiddler on the Roof.
Yes, you read that right.
I'm not completely sure what this is from. The best I can determine is that it's a TV special called G.I.T. on Broadway. Mind you, I have no idea what that is, but it's a start. And it's from 1969. It exudes 1969. It's even introduced by Diana Ross.
The video quality is poor. The performance is worth it.