Previously, I spoke of the "ontological significance" of music, as a form of art. Below, I will attempt to explain this in greater detail (drawing heavily on Heidegger's writings) while avoiding excessive and cumbersome terminology that may be unfamiliar (however some precision and clarification is necessary [I will introduce a few terms]).
I raised the issue of "ontological significance" to contrast it with the common understanding and appraisal of music and art in general, which concerns only the "thingly" aspect of works of art and views them as sensory objects (which are thought via "aesthetics"). One of Heidegger's examples from Being and Time displays this opposition. A merely descriptive ("ontic") account of a hammer speaks of its weight, size, form/shape, material, quality of manufacture- its metal head, wooden handle, etc. An ontological understanding reveals the hammer as a tool which hammers, as equipment for building, as a creation of man that aids him in constructing his dwellings.
The ontic, or merely descriptive account, is not "incorrect" if acknowledged as an aspect of something's being- the hammer certainly is of metal, wood, etc.- but arbitrarily bounded and woefully mistaken if proclaimed as the whole of its being (the hammer is not only pieces of metal, or wood). That it is not limited to its descriptive components is revealed by its name- it is called "hammer" (not "metal and wood") because it is for hammering, its thingly qualities serve in an equipmental fashion that is significant to man. This significance cannot be grasped by an ontic (descriptive) account, but only through an ontological understanding.
How does this apply to music as art?
The evaluation of art via aesthetics is an ontic approach. In visual art, we speak of elements. In music, pitch, rhythm, timbre, texture, dynamics, composition, etc. serve this same purpose. All these descriptions are of the thingly aspects of visual or sonorous "objects"- they classify, categorize, and evaluate the sensory aspects of art, they dispose. In contrast, the ontological understanding discloses the significance of the art as an art-work, which is not merely a collection of pigments, lines, or sonic disturbances. Nor does a cheap appeal to its "emotive" qualities break out of the ontic- this can be just as calculated and descriptive as the purely formal physical descriptions (however, evocation of honest and fundamental moods is certainly a part of art [wonder, daring, anxiety, affection, etc.]. I am distinguishing this from the cynically calculated manipulation of popular "emotional" responses).
Unfortunately, our direct parallel with the hammer fails us at this point- the ontological significance of the hammer is equipment- surely a work of art cannot be viewed in such crude terms, even if art-objects are commonly used as such (even to the point of art being erroneously conflated with equipmental "use"). "What is art?" This is certainly a complex "riddle" and one that I cannot presume to "answer" here. However, the example of the hammer points us in its direction, so that we may come closer to an understanding of art.
The ontological significance of the hammer is revealed when we pick it up and use it for hammering, when we are engaged with it as equipment. Similarly, we will come much closer to art if we comport ourselves not merely to ontic aspects of the medium of art, but the work of the artwork itself.
Art is not a mere thing, a conglomeration of sensory experience. These elements compose the thingly aspects that allow us to experience the art (they are the vehicle for art) but they are not art itself. Similarly, the metal and wood of a hammer allow us to grasp it, provide the rigidity and leverage necessary for its task, but are not "hammer" or equipment individually, or as a union of "metal + wood".
Art is not merely equipment (either of the physical or psychological). If it were, "art" as a concept and term would be superfluous, as it would hold no higher status than any other tool, be of no more significance than our lowly hammer- certainly this is not the case and this view seems unpalatable however cynical we may be. Art may be abused as equipment by "culture", the advertising and "art" industries, or connoisseurship (the elevation of aesthetics to a science) but it historically serves a different purpose, despite all attempts to render it as equipment. It is by its nature un-economical and "useless" (equipmentaly), and serves unexplainable (or "irrational") spiritual, religious, communicative, symbolic, conceptual, or emotional forces. When we comport ourselves to artwork in an equipmental fashion, its meaning flees us- we are left with a repulsive and yet numb feeling.
It is inappropriate to look for significance of art in a thingly (ontic) or equipmental (incorrect ontological reference) orientation. If I cannot say decisively what the "correct" orientation is (if there is even such a "thing"), I can at least point to it: the art-work discloses a world. World is not thought here as something limited terrestrially, a collection of things (beings) that are, nor some high flown fantasy. The artwork must open up a space for more primordial thoughts and moods, to preserve strife (which does not mean a mere quarreling). Here I am straying into very difficult territory, and am drawing too directly from Heidegger's The Origin of the Work of Art (which has heavily influenced this entire writing of mine, but I have deviated from it significantly until now). I will leave this difficult ground to more accomplished thinkers, lest I merely mimic their words (however unsatisfactory it may be to you all, I cannot furnish a robust account of art or our relation to it- this is not due to a lack of thoughtfulness, but the difficulty in communicating such things, and my limitations with language. I have pointed in its direction, and I trust this is enough for now).
Too often, an ontological understanding of art is used to dismiss aesthetics and the ontic approach in general. I think this is too strong of a reaction, and a misunderstanding of how we have access to art. The vehicle, the aesthetic, is indeed necessary for the communication and disclosing of the art- it tempers it, gives it its character, and mirrors the art's disposition. One would not choose Gorguts thinking it discloses a world in the same manner as Bach's organ works. Clearly, aesthetics is very important. However, our understanding must not be bound or limited to it, and this is the purpose of introducing discussion of "ontological significance"- not to negate the role of aesthetics, but to insist that it alone cannot be called art, as this misunderstanding abandons art.