It sounds like you were more comfortable at Andover. That’s a good reason to choose it.
It sounds like you didn’t feel as comfortable at Choate. I suspect you would find your people there too, but that’san importantthingto stay tuned into.
My guess is that you would work quite hard at both. I would definitely figure out, though, which will be most convenient for your cello practice, lessons, etc as this sounds important to you.
Both are equally excellent schools so you can’t make a bad decision.