G10H 2220/181

User input interfaces for electrophonic musical instruments for string input, i.e. special characteristics in string composition or use for sensing purposes, e.g. causing the string to become its own sensor by nonresonant wave interaction, i.e. string sensing using wavelengths unrelated to string resonant wavelengths, e.g. ultrasonic waves, microwave or light waves, propagated along a musical instrument string to measure its fret length, e.g. for MIDI transcription