196776 ⎘
Input/output interfacing specifically adapted for electrophonic musical tools or instruments; User input interfaces for electrophonic musical instruments; Beam sensing or control, i.e. input interfaces involving substantially immaterial beams, radiation, or fields of any nature, used, e.g. as a switch as in a light barrier, or as a control device, e.g. using the theremin electric field sensing principle; Radio control, i.e. input or control device involving a radio frequency signal Use of microwaves