I hadn't seen this posted before
http://youtube.com/watch?v=4fJf7fjsoSI&feature=related
Unfortunately the audio/video quality isn't as good as the What's Going On clip that's been out there for a while - but I didn't think there was any more of that performance on the DVD. If there is more, as this clip suggests, it might be worth buying.
A shame that you have to strain to hear Jamerson at times and the most the camera man gets of him is half of his right hand. Great stuff anyways.