writing and/or improvising

Just read an article by Keith Sawyer on improvisation in teaching. His point is pretty much this: "Scripted teaching, bad; improvised teaching, good." Okay, it's not quite so binary, but he does explore teaching as performance. In his view, teachers should be encouraged to alter teaching materials or methods to best suit their students.

In thinking of how to apply this to the teaching of writing, I've been reflecting on what it means for a writer to improv (or to improvise, or to "do an improvisation"). I even went so far as to look it up on Wikipedia. According to someone somewhere, improv is the "practice of acting, singing, talking and reacting, of making and creating, in the moment and in response to the stimulus of one's immediate environment." In exploring the concept of improv writing, I've been wondering how any form of writing can not be considered improvisation. Isn't it all in the moment, making and creating? Some might argue that this could be the case for creative writers, but what about boring technical writing? I would think such writing is still responding to stimuli in the immediate environment (watch this machine do something; now describe how it works). In jazz, the musician has several tropes they can turn to in improvising. Isn't this the same as the writer's bag of tricks--let's try second person present tense this time; let's remove the punctuation and see how that looks; let's kill the guy at the end of the first chapter... Nothing but trope. And yet...

And yet, does the analogy continue: if there are times when a musician is not improvising, are there times when a writer is not improvising? A musician just reading music and playing what she or he reads would not be improvising. Is there a time when a writer does this--"just reading music"? It doesn't seem to work that way--it seems the writer is always creating, putting words into new orders and shapes. But maybe I'm biased (I consider myself a writer, I don't consider myself a musician).