I have some sheet music which belonged to my mother... But I can only play by ear these days.
But I have a theory that if you have two musicians, both trained and able to play anything that is put before them, but only one of them has the ability to play by ear as well, then he or she will be able to project more life, beauty and expression than the other.
Montaine and Jean-Claude inherited their love of music from their mother. They sang together, played by ear on the old upright that someone from the big house had thrown out and they had retrieved.