Remote key fingering indicator, i.e. fingering shown on a display separate from the instrument itself or substantially disjoint from the keys

Full Title

Input/output interfacing specifically adapted for electrophonic musical tools or instruments > Indicator, i.e. non-screen output user interfacing, e.g. visual or tactile instrument status or guidance information using lights, LEDs or seven segments displays > associated with a key or other user input device, e.g. key indicator lights > Remote key fingering indicator, i.e. fingering shown on a display separate from the instrument itself or substantially disjoint from the keys