Martin, F. David.  “Unrealized Possibility in the Aesthetic Experience.”  The Journal of Philosophy 52 (July 1955): 393-400.

Abstract

This article is an examination of the role of "unrealized possibilities" insofar as they arise from the tensions and unexpected resolutions which the participant projects in his appreciation of pure music.  Association of these feelings of unfulfilled anticipation with anything external to the music is rejected, and it is argued that unrealized possibilities enrich the aesthetic experience, provided that they remain grounded exclusively in the sensuous "given."  making use of Whitehead's concepts of physical, conceptual, and propositional prehensions, the article concludes that unrealized possibilities are immanent in every artistic form.  [Abstract from The Philosopher’s Index]