Oberlin College does have a musical studies major (acceptance into which is by audition) that does provide some of the resources (including some courses) of the conservatory to those enrolled strictly in the college. I neglected to mention that in my previous response.
I don’t know the particulars of how the music program works at Barnard - although I know the students can study in the music department at Columbia, and take private lessons with great teachers. Sarah Lawrence might also be worth a visit if you have time. And, in Boston, you could look at Tufts? It’s well known for IR and has a strong music department.
We have personal experience with Tufts’ wonderful music department 
All the schools mentioned are a good idea to look into. You can tell a lot from websites, honestly. I am sure you have done this thoroughly. Reading course descriptions, the required curriculum for major(s) and minor, faculty bios are all really helpful. Going to concerts at the schools is helpful too, and gives you info on vibe as well as level.
Barnard is next to Manhattan School of Music. And across from Columbia. I am pretty sure there are some opportunities for Barnard students at MSM but check it out- my info is dated!
People seem to love Vassar for music and academics. Wesleyan is strong in world music.
Good luck!
Wesleyan has a recording studio:
http://newsletter.blogs.wesleyan.edu/2015/11/24/redfeatherstudios/
…as does Skidmore: http://www.skidmore.edu/music/faculty/holland/studio/right.php#performance
I would consider looking at Belmont in Nashville. Excellent recording facilities for students and access to “music row.”
thanks again all, great suggestions, much appreciated