Re DD and the music, I think of it being quite typical for musically gifted people to be able to play music by ear after having heard it, even without training. She will try to do that, but she's not especially great at it--it takes her a while to pick out even a simple tune (eg, Star Wars theme). To me, what's weird is remembering the full written score to a piece and then being able to effortlessly play it on another instrument (that she's also not been taught). We don't actually think of her as terribly musical. She also can generally play all her band music (to be fair, it's still easy, as she's been playing 6 months) without the sheet music. Just naturally happens for her by accident.

BTW, she does have synesthesia, though I haven't heard her comment that it affects her sense of music...but who knows.