Another issue concerns the role of "distance" in transformational theory. In the opening pages of GMIT, Lewin suggests that a subspecies of "transformations" (namely, musical intervals) can be used to model "directed measurements, distances, or motions".
A related concern is the function of "distance" within transformational theory.  Lewin's work in GMIT proposes that specific types of transformations, particularly those involving musical intervals, can be utilized to represent "directed measurements, distances, or motions."