Abstract: A method of treating a nylon or other non-ferromagnetic musical instrument string so that its movement is detectable by a ferromagnetic pickup includes applying ferromagnetic material to a portion of the string when the string is mounted to an instrument. The preferred method is to paint the string with a fluid material comprising a suspension of nickel particles in a solvent, and permitting the solvent to evaporate to leave a residue of nickel particles on the string.

Abstract: An electronic music system for computer-controlled interactive practicing and learning to play a guitar includes a transducer which is detachably securable to the guitar and generates analog signals representing the playing of the guitar, an interface for converting the analog signals to computer-processable digital signals, and a computer for receiving and processing the digital signals. The system uses a communication protocol which employs time stamping of data to permit use with ordinary guitars but without high speed frequency determination. The computer provides audio and video outputs including staff and guitar fingering representations of notes, chords, scales, compositions, and like musical structures, both to teach the user and suggest music to be played by the user and to illustrate what the user has played. The system is operable in several modes which may be controlled by the user by signals produced at the transducer.