Thank you, Tony, Montunoman, W Tracy Parnell, John for your comments.
I just listened again and pieces of music like this presented really make you wonder why do I need an arranger KB, styles etc,
to create music with so many other choices out there....?
In my case I can only answer to this question with this very video: mostly I prefer either do everything on-the-fly, or not to do it at all. Step-by-step kind of work is not reality for me; after all, to me playing music is about emotions, and when it becomes more like working in the office at your desk (I mean computer based setups) I don’t really picture myself in that scenario. In the same time, commercial music is indeed more like engineered rather than played, and arranger keyboards don’t have much to do with that process.