Composition is a singular becoming.
Not only is it impossible to reduce composition to something other than itself, but every definition, within a given epoch, is relative to that epoch—that is to say, to the history that gives rise to it. There is no eternal definition.
To speak of composition is always to remake music. This becoming seems to be autonomous; it seems possible for the composer to find beneath the historical accidents a necessary consecution: the notions introduced were necessitated by the solution to a problem—and by virtue of their sole presence amongst the notions that already existed, they pose, in their turn, new problems.
There really is a becoming: the composer embarks upon an adventure which can be arrested only arbitrarily, every moment of which endows it with a radical novelty.