38. An arrangement as defined in claim 27 wherein said means continuously responsive to operator input consists essentially of; a movable first surface; a fixed second surface; a conductive coating under said movable first surface, and a resistive coating on said fixed second surface, arranged to have alternately perpendicular directions of voltage gradient supplied to said resistive coating through switched connection to a source of fixed potential; and voltage-detection means for timed decommutation of the voltage transmitted from said conductive coating underlying said movable first surface as picked up from contact with said resistive coating, into one signal for the component of motion in each of two coordinate directions.
27. The arrangement as defined in claim 25 said means continuously responsive to operator input measures motion into substantially perpendicular directions; and further including transducer means to resolve said motion into components in the two substantially perpendicular directions; said system further including frequency tuning means; whereby one of each of said components of motion affects the frequency location of one of each of said resonant peaks or formants.