What Makes Mature Playing? Part I

For the past several months I have been working on a profoundly lyrical Bartok piece with a young man whose physical and mental coordination is severely challenged by blindness, autisim, and other development issues.

Today I found myself describing to him that what makes his playing of the piece grown up is the fact that he can exercise choices about how he plays each phrase.  In his case the choices are extremely specific: hand in this position, use those fingers, play louder than you are comfortable playing, let go of the sound before you want to--that sort of thing.

I stopped myself in mid-sentence as I was going to say that children do not have the option of making those choices.  I would have been mistaken: I have heard children do just that.

On the other hand, I have heard many mature musicians who seem not to notice that they have choices as they play.