Either one is forced to considered every sound-event is the consequence of a choice (conscious or other wise) by a single composer, or consider the composer as part of a tradition of musiking of which this work in its particulars and similarities to other works as a particular instantiation or draft.I've posted about the nature of works a couple of times. I can appreciate that musical decisions come from a ground of possibilities, just as the fact that I'm using American English here sets the range of possible utterances in this blog. But our musical intentions, why we decide to play this piece and not that one, how we choose from an infinite set of possibilities to this specific instance, is a choice for which I take responsibility, which I own. There are many factors involved in this decision, some of which I made recently, some of which I made years ago, and some of which no doubt I would be unable to articulate.
One of the reasons I pursue music is exactly this state of flux. Music is the most participatory art because of these ambiguities. When I study and learn to play a piece by Morton Feldman, I establish a communication with him that is stronger than listening to a CD or reading an interview. Does it matter that my performance of Feldman's won't be as authoritative as Aki Takahashi's, or that her performance will be heard by thousands of people whereas mine will be heard by only a few? The range of performances that will be recognized as "Morton Feldman" is very wide (even including a reduction of an orchestral work to a "power trio" of electronics, piano and percussion), and therein lies the mystery and the joy of music.
Douglas's comment brought to mind a recent post from Matthew Guerrieri on the famous Either/Or by Søren Kierkegaard, which identifies the decision as the discontinuity that separates faith from despair. Given the irrational understandings that let me play and compose, and even though I don't consider myself to be a religious person, Kierkegaard's perspective illuminates why I need to keep paddling even though I'm adrift in a pretty big body of water.