I just remembered another "Preston Funny"....
Sometime in October 2010
Mom is sitting at her computer and Preston climbs up onto the piano and starts to play it. He is being very good, not banging the keys, and paying careful attention to use individual fingers instead of his entire hands or fists.
Then he turns to mom and says, "Momma sing?"
Mom started to make up a song and Preston continued to play the piano, while periodically looking over at mom with a very pleased look on his face.
Preston just performed his first accompaniment to a singer.