After experimentation with monochords
of two, three, or even four strings had occupied theorists and probably musicians also in the fourteenth century, it seems that the monochord was transformed into an instrument of some eight strings tuned in unison, with multiple mobile nuts, one for each pitch: these were nothing less than a new form of key, very long as compared with those of the organ, each carrying implanted a perpendicular blade; it was this blade that represented a segment of...