My intuition is that I've never really thought about this particular issue.
I probably need to read that book.
Years ago, myself and 3 amateur musicians, one actually a bit more accomplished that the others started an improv quartet without really meaning to. We weren't consciously starting a band. We just started recording. We didn't talk about any musical parameters such as key, time signature or any of that. We just played the tracks for the recordings in one take each on an old 4 track Teac machine (reel to reel). What we produced was quite startling even to us. Not only did the recordings sound planned, but we found our improvisations nearly impossible to reproduce when we tried. Since those initial experiments the same four musicians have continued the experiments regularly, but not frequently. We extended it to performing live pretty early on and even to using instruments that we were unfamiliar with. Currently I am working in a trio configuration that largely works the same way. It is amazing what can be accomplished when the mind is free of expectation. Most of the musicians that I have worked with are totally afraid of this approach and will generally get stuck in some "groove" which too often becomes the same thing as a pre-meditated rut.
With pre-meditated music, I find that I really need to over-learn a tune to be able to play it well. I need to try to play it in different positions, vary the bow strokes and go through all kind of high jinks before it just flows effortlessly. If I'm playing bass guitar or classic guitar it is the same thing. If I just play without thinking, there are usually no wrong sounding notes. Currently I am concentrating on sight reading charts, but it should never be thought that this is how any music originated, just how a particularly good insight is preserved after the fact.