Music is one of the most powerful familial tools available. I am not talking about music, the external experience so codified by pseudo-scientific measurements and applications. Rather I am talking about the internalized music expressed in the desire, not to be confused with the ability, to play.
In one family in my studio there is an autistic boy whose only developable contact with other humans is his musical ear. When his older sister, who is not blessed with the innate ability to respond in any obvious way to what she hears, expressed a desire to play it was clear that a whole range of emotional changes would result.
Today she confided two things to me: It took her a long time to realize that she wanted to play not for her brother's sake, but for herself. She knows that he listens as she struggles through her pieces, though he does so from his room with the door closed. But, whereas he used to "steal" her pieces by playing them with greater facility than she will ever have, he has learned to respect her musical space.
Naturally in a family with such a needy child everything seems to be dominated by that child and determined by his needs.
She confided also that her cousins and aunts and uncles are mystified that, though she takes piano lessons, she does not perform for them. But she is clear that that is not her goal. She plays what she plays as she plays it for herself. The depth of the work increases with no judgment imposed by the cliche of "piano lessons."
What an extraordinary privilege to work with such a person.