I have 4 year old who is reading notes and enjoying his piano lessons (practicing is a different story). I think this is the right approach for him. He likes reading the notes and breaking the code so to speak.
He started playing immediately, first using the finger numbers, then names of notes and now staff. He is a very good reader and I am sure that helps a lot. From what I've gathered from his teachers most 4 year olds are not up to reading notes on the staff though.
DS6 started lessons in September too and is wonderfully independent. I don't ever have to practice with him and I never have to push him to do so. I think he is the person who needs to see the notes. He is very visual and he would probably have hard time playing by ear only. Plus he has to get it right.
