  In this context ‘monism’ is simply a label for the idea that all works of art fall within one ontological category, such as abstract particulars. A prevalent argument against this sort of thesis rests on the distinction between performance and non-performance works: many musical works can be performed by various persons and on various occasions; a painting cannot. Having described such distinctions amongst works of art, Wolterstorff concludes tersely that “Works of art are not all alike in their ontological status” (1975, 230). According to Stephen Davies (1993), we need not look beyond the art of music to find grounds for rejecting ontological monism. More recently, Robert Howell (2002a, 2002b) has argued that if the term ‘work of art’ covers artistic improvisations, the various utterances referred to as ‘oral literature’, and such items as paintings and scored musical compositions, then no single adequate ontological category is to be found. With reference to artists’ stipulative authority over the “features and boundaries” of their works, Sherri Irvin declares that “Any claim to the effect that all works belong to the same ontological category will thus come out false or uninformative” (2008, 1). Yet as will become clear below, monism still has its proponents.