„It is improper, to expressly pursue the Urlinie in performance and to single out its tones... for the purpose of communicating the Urlinie to the listener." Rather, "for the performer, the Urlinie provides, first of all, a sense of direction. It serves a somewhat equivalent function to that which a road map serves for a mountain climber.“
— Heinrich Schenker
Das Meisterwerk I, p. 196. Translated by Kalib, vol. 2, p. 147. Quoted in Burkhart, Charles (1983). "Schenker's Theory of Levels and Musical Performance", Aspects of Schenkerian Theory, Beach David, ed. New Haven: Yale University Press.