How can anyone dance and play the arranger?

Unless you mean someone moving with the music etc.

There was a video posted here about 5 years ago, with a Dutch (or maybe German) guy who was paying a Tyros in a kind of club, lots of lights, dance floor etc. If my memory serves me well he also sung, not sure though

He was playing standing up and I remember he moved a lot and seemed to really enjoy what he did, his playing was quite good.

I tried to search for the video to no avail. Perhaps a member from that region can help us.