I think you’re good for all the schools you listed, but Stanford might be a slight reach (but they like quirky applicants, so you have a shot!). IDK if you’re able to participate, but the YoungArts competition has a music (including harp) category that you might be interested in. Best of luck!
Chance me back? http://talk.collegeconfidential.com/what-my-chances/1968508-chance-me-for-selective-top-schools-ill-chance-back.html#latest