Those who, at one time or another, have struggled with Noam Chomsky's Aspects of the Theory of Syntax probably remember his "fundamental distinction between competence (the speaker-hearer's knowledge of his language) and performance (the actual use of language in concrete situations)." Section 2 of the first ("Methodological Preliminaries") chapter is entitled "Toward a Theory of Performance." It runs about six pages in length, leaving the reader with the impression that performance is little more than as set of "implementation details" that can be derived from those models behind his theory of competence; and that is pretty much all Chomsky had to say about performance in his 250-page book. It is also worth noting that Chomsky believed that any model of semantics would similarly be grounded in a model of syntactic competence.
Revisiting Chomsky reminded me to how important it was that Jürgen Habermas chose to shift the playing field from a theory of syntax (or, for that matter, a theory of language that afforded less secondary attention to semantics) to a theory of "communicative action," returning the emphasis to performance as a particular form of human behavior through which communication takes place. This shift had it origins in his search for a "universal pragmatics," which serves as a valuable reminder that, while pragmatics had been a major element in semiotic theory, it was totally absent from Chomsky's Aspects. Whether or not Habermas' subsequent Theory of Communicative Action ultimately resolved that search for a universal pragmatics is less important than the fact that his research introduced a major paradigm shift from attention to language-as-artifact to communication-as-behavior.
I bring attention to this paradigm shift, because I think it may guide the way we think about the performance of music, whether or not such performance conforms in any useful way to Habermas' model of communicative action. Most important is that Habermas' theory is grounded on the principle that communication spans the three "worlds" we inhabit: the objective world, the subjective world, and the social world. The performance of music also spans these three worlds, and I shall now try to outline why I take this to be the case.
In many ways the objective world of music performance is not that different from Chomsky's world in which linguistic performance is derived from the abstract structures of syntactic competence. As its name implies, the objective world is a world of objects; and there is a rather wide variety of objects that figure in the performance of music. From a Chomskyan point of view, the primary objects would be artifacts of notation; and performance is a matter of how those artifacts are interpreted, very much in the same vein as the approach to performance in Aspects. However, where music is concerned, the instruments that produce the actual "acoustic signals" are also objects; and there are many rigid approach to pedagogy that attempt to reduce the basics of performance to a relationship between performer-as-object and instrument-as-object, trying to "micromanage," so to speak, the physical actions of the performer. Similarly, we should also think of recordings of performances as objects, which is why I have had particular interest in the extent to which the visualization of those objects may facilitate (or impede) our skills in listening. Finally, just as there is a pedagogical strategy to viewing the performer as an object, there are (highly?) limited ways in which the performer may view other performers as objects, providing such information as specific cues or the general beat, which rarely proceeds with the consistency of a metronome.
However, if we are to view the performance of music as a communicative action, then we need to recognize that, like any other communicative action, the actions themselves are motivated; and, when we introduce the concept of motive, we move from the world of objects to the subjectivity of the individual doing the communicating. In the bluntest of terms, you cannot communicate without having something to say and without having a reason to say it. It is that need for a motivated reason that led (motivated?) Habermas to view communication through the lenses of his "universal pragmatics;" and it is this move to the subjective world that Chomsky tried to abstract out of the picture of linguistic behavior. Unfortunately, our understanding of this subjective world is probably the weakest of the three worlds of the Habermas framework. The problem is that there are few data points upon which we can draw for why people choose to perform music at all; and most of those data points come from interviews, which have a surface structure that may not always reveal a more informative deep structure. One might suggest that an understanding of the subjective world requires a shift from the mindset of music theory to that of psychoanalysis. However, the one time I heard a psychoanalyst lecture about music, he was discussing Ludwig van Beethoven; and there were serious flaws in his reasoning!
We understand the social world better because performing music is almost always a social matter, within which very rich communicative actions take place. In chamber music those actions take place through the tightly-coupled social network of the entire ensemble. In a larger ensemble, such as an orchestra, the network is more hierarchical, usually involving intervening layers of concertmaster and section leaders between most of the performers and the conductor. The study of this social world is also facilitated by the extent to which most (if not all) of those communicative actions need to be explicit. Thus, we can take advantage of video documents of performances to inform us about those communicative actions in ways that audio recordings can never do. Nevertheless, we need a better understanding of how to read the "raw data" of such video recordings, just as I (and many others) have tried to take on the problem of visualizing the contents of audio recordings. Even then, however, any video document is only a fragment of the entire process, since it abstracts away all of the communicative actions that have taken place in the rehearsals (which is why not all communicative actions are necessarily explicit) that preceded the performance (not to mention a richer history of communicative actions in the "life story" of the ensemble itself).
Perhaps the only conclusion one may draw from this excursion is that any analytic study of musical performance involves more difficulties than any mere human scholars can manage. However, this is one of those rare cases where I have to confess to being optimistic about technology. If nothing else, technology continues to make progress in making manageable large masses of data previously thought to be unmanageable. Such manageability is often arrived at through groping efforts, trying out certain information processing techniques, discovering their limitations, and developing new techniques to compensate for those limitations. However, if we compare our understanding of musical performance today with what we knew fifty years ago, when the very idea of "information processing" was just beginning to rear its head, there are plenty of grounds to conclude that we have made progress in our groping. If my "big picture" of musical performance is still beyond our current scope of understanding, it may still help us to choose where we next want to grope.