At the improv workshop, the teacher said his system regarded musicians as having two types of consciousness. One is attention all over the place kind. Though you are supposedly engaged in playing music, that type is thinking about how long you should solo, how much better or worse you are than other players, why doesn’t this piano have better action, the colour of the shirt of the person in the front row, what you did yesterday, what is for lunch – all over the place mind like a fly in the room going everywhere.
The second mind listens while playing, has a other experience, brings empathy. His point was that the second mind is a better musician, the one you should encourage and by virtue of reaching it the first one has less grip, disappears for a bit. Gets out of the way.
I think what he was getting at was that getting there is as simple as just listening.