Well, I really don't know why there is a reason fort he audience to know what is going on.
They do not need to know. They want to know. The performer and audience seek an emotional relationship.
Maybe Kraftwerk have already answered this, but if at the end of the TED performance they had revealed that Ashanti was an android would the audience have been less or more impressed?
Besides, if the audience doesn't need to know, then why one would play in front of an audience? A violin player is a beautiful thing to see, and even if it's not clear in every minimum detail what he/she's doing, you _perceive_ it. It's a whole world of movement, kinetic energy, sound and other subtlety coming together.
A dj dancing to the beat is not that beautiful.
control, why one uses gestural control at all?
I have explained above what the movement of the body does.
Marco's disappointment is understandable (sorry if I misinterpret this Marco). When I watched "Top of the pops" as a teenager, like many kids of that age I was outraged that the performers mimed. Sometimes you could see their instruments were just props. It is very insulting to someone who has invested effort and emotion to an activity to see it trivialised to a banal fashion statement. Like a soldier seeing their regimental badge worn as a punk accessory.
Andy, my judgement is surely partial. However, as I stated in another email, I'm more concerned about the bold claims "we make the future", as long as they are backed by something which is not "that" innovative they look incoherent. I guess, I'm being very ingenuous.