That's great advice thank you. We do have a medium size keyboard and he's got a couple small guitars he loves to run around with. He always tells me they are out of tune and he will put his ear up to the guitar and twist the knobs (whatever they are called) and listen and twist the knobs some more — we have no idea where he learned that but I'm guessing school.
Makes sense to have him learn how to read music first via the keyboard