I wanted to post this for you. I found this recently in one of my frequent Pink Floyd Youtube sessions and must admit, it put a different spin on my opinion of the May, 2011 O2 Arena concert that I commented on with David joining in for comfortably numb. Seeing the interaction between David and Roger (and one other original member as you notice at the end - I'll leave it a surprise if you haven't seen this behind the scenes video) put a different 'spin' on the performance and my opinion of it. David seems much more 'lucid' in this video and Roger actually admits he used to be an 'ass' in his younger years. I enjoyed this...