Returning to an earlier topic, it seems clear that building a growing body of theory over the years leads to an increasingly rigid context for music. The process by which anything unfamiliar is perceived and apprehended is necessarily conditioned strongly by the discourse surrounding it and the functional roles assigned to its constituent parts. Whether the theoretical framework one seizes upon fits a particular piece especially well is something which might be quite difficult to determine, and this is one of the reasons that first impressions can be so lasting. Indeed, there are a variety of frameworks even within the Western tradition, something which is demonstrated only too clearly if one brings together musicians from a variety of backgrounds and ask them to discuss theory. Even basic terms have differing associations and communication can be difficult. If we add the fundamental distinctions between traditional approaches in other cultures, the potential for miscommunication is large, and the danger of modifying the substance of a tradition by altering its basis is real.
In that sense, the multiplicity of musical styles which he have today can become especially confusing when they intersect in theory. Taken on their own terms, they evidently make good sense, and of course the variety is something I generally applaud. However, there is a bewildering overlap in terminology, with the same words meaning entirely different things to different musicians, or even somewhat similar but not identical things. The latter can be even worse, because it presents the appearance of communication. Fortunately, where we cannot be so easily confused is the sonic surface itself, given our wealth of recorded information. Even live concerts from a variety of traditions can be attended today. This provides a way to relate theoretical discussions to concrete instances, and indeed I can only marvel at the pre-recording discussions of music from other traditions. Without the reality of hearing it, I imagine the readers' mental image to have been quite different. Of course this problem helps to explain the seeming perversity with which other structures, such as Indian modes in French organ music, were used in the early classical fusion music. Unfortunately, the latter provides even more impetus to the bifurcation in theoretical language with which the modern practitioner is presented. Words were injected into musical discourse at multiple times, and with differing meanings. That is the reciprocal process to the one in which meanings diverge along with traditions, and yields a complicated ramified structure to these associations as opposed to a simple tree. It could hardly be any other way, as complex interactions of this sort are the very stuff of art.
Yet it is perhaps curious at first that the interaction would occur at both the practical and theoretical level, and indeed yield an even more unstable relationship between the two. The simple fact is that some "new" and poorly understood theoretical idea can easily serve as artistic inspiration, something which goes a long way toward explaining the resulting tangled mass of terminology. Just as we had looked at notation previously, the dual creative aspect of music, namely that it is often composed and then performed separately, serves as a sort of "slingshot effect" by which to intensify this relationship and indeed to contort the nature of theory itself. Theoretical relationships assumed by the composer may be necessary for exegesis by the performer, and are thus reinjected quickly and perhaps idiosyncratically into this loop. By contrast, whereas the shape of Rembrandt's brushes might be interesting knowledge and indeed helpful toward increasing our appreciation, we can nonetheless look at the surviving artifact in all its glory while in complete ignorance of such things. Dual creation in music confuses the nature of theory by making some theoretical training necessary for practice, yet the nature of theory means that there is never a clear stopping place. The abstract nature of music as an art makes these theoretical ideas more interesting starting points for creation than they would be elsewhere, and this yields a tenuous relationship between music & mathematics among other things.
Theory is perhaps more important than that. It conditions our apprehension of music in fairly concrete ways. Faced with a barrage of notes, few people can absorb them in one breath. Rather they must be broken into smaller chunks, whether melody or chord or any of a number of other constructs, and learned piecemeal. This is a typical cognitive strategy, and one most people must use out of necessity. Needless to say, we are conditioned to make these divisions in particular ways, some subconsciously and some more explicitly by theory. This is one way in which theory can help our understanding of music, because it can provide a means by which the otherwise inaccessible can be made accessible over time. When it comes to music, simply knowing the theoretical function of a note or other construct is not enough to make it truly accessible... that is a natural first step, although not necessary. One must still resonate with the music in some way, on a personal level. This is perhaps the main area in which theory can prove deceptive, because theories learned for other musical styles can lead us to divide and attempt to understand a new piece of music in ways to which it is simply not amenable. Anyone completely baffled by music from another culture knows this first hand, as well as that merely asking oneself not to jump to erroneous conclusions is not sufficient. It can be a struggle. A way out of this problem is paradoxically to learn more theory, because a closer analysis of our own theoretical underpinnings can allow us to identify assumptions we are making unknowingly, and to eliminate them when convenient.
Theory also happens at another level, in that people come up with various ideas on "why" some piece of music works as it does, or even what makes us like music in the first place. For most people, these theories have little direct impact on appreciation, although they can sometimes affect how music is written. They provide the most diffuse level of theory, that which is perhaps most closely analogous to theory in other disciplines, and give us a way to take a brief look at theory per se, as truly distinguishable from practice. Unfortunately, this level usually also includes normative judgements which condemn some musical technique of which the author disapproves. Since I see such things almost daily, I am driven to wonder if there is something about music which solicits them. Perhaps it is the degree of abstraction, although I am unsure. Certainly the extent to which there is no clear demarcation, both in the actual steps of production for music and in its connection to theory, tempts one to take another seemingly small step and prescribe some aspect in more detail. This process is reciprocal to the one by which the sonic surface of a piece can be prescribed with increasing detail, and a factor in the eventual formation of multiply distinct traditional paths. In that sense, theory can be taken as a broad label for practice.