As we live in a world full of technological gadgets we have come to be dominated by buttons. We have a world of options at our finger tips. This is also true in the world of music. It has been extended to knobs, sliders and touch pads but the idea is to have a one (or in the case of an XY pad two) dimensions that are mapped to parameters. Virtually every controller does this.
Even the mighty Eigenharp is just a collection of buttons. Ok, granted, buttons with multiple dimensions but we still have a map between performance parameters and synth parameters.
I have to admit that getting back into guitar via the Moog Guitar has been a great experience. Simply because technique involves no mapping of parameters but direct contact with physical objects (strings and frets).
So to the Korg Wavedrum which is a wonderful instrument with no MIDI at all. The membrane of a drum can be used with great expression. An entire musical language is created by the Indian tabla for example.
I love how Moog Music has also brought back the idea of an envelope follower letting the natural dynamics and a signal control a filter.
These ideas begin to bend the button dominated musical world. I hope to see these more physically based ideas of control begin to take root and grow into even more new products.