Occasionally I talk about what I call “offloading the moment.” The idea here is that there are decisions that one should make while practicing music and there are decisions that one should make while playing music. For instance, what finger to use to play a particular note in a song is a decision that should be made while practicing. You don’t want to be struggling with that one while actually playing.
Ideally, while playing, your mind is pretty free from granular decisions like what finger to use, or what chord is coming up etc. That stuff you should just “know.” Because you already figured it out and practiced it ahead of time.
I’ve been reading the book “Music, The Brain and Ecstasy” which is essentially about how the brain listens to and performs music. There’s a passage in the book related to the offloading the moment concept.
…experiences suggest that the better part of virtuosity may have little to do with gross neurological advantage. Instead, virtuosity may depend on how the musicians mind is organized during performance — how the body is comported, how attention is focused, and above all, how imagery is brought to bear. In this view, virtuosity is mostly a matter of abstract planning, not raw muscle control.
In essence, you shouldn’t be thinking about the details when playing (details like what finger goes where). Instead you should be thinking about the overall structure of the music.
The book continues.
The virtuoso develops mental hierarchies that are deep and flexible, hierarchies that are so well-trained that they function automatically at superficial levels, freeing the virtuoso’s mind to concern itself with larger musical structures. Working with larger structures gives the virtuoso time to consider every musical act before it is made. The musician is no longer chased by the multitude of notes, attention is no longer pulverized by a stampede of details.
This is, I suspect, all related to what some people call the “flow state.” In this state, you are operating somewhat automatically. The mind is really just guiding the big picture whereas the minute decisions have been programmed in through practice.