Here’s an experimental musical keyboard which is a MIDI controller based on relativity.
Israeli industrial designer Eitan Shefer has created the Samchillian keyboard, taking a novel approach to a musical instrument where you don’t play specific notes but select how they relate to the ones before them. For example, if you’re playing a C and then want to play a D, you just push the +1 key. There are two directional keys, 16 relative keys and eight finger positions, and when you want to bend the pitch or manipulate the filters, you tilt the unit from side to side. It’s also customizable for large or small hands. Check out the beautifully-produced video, and you’ll quickly understand how it works. Wonder how difficult it is to learn?