I strongly advise you to read this essay from the Peabody site about different types of music students and the best program fit for each. http://www.peabody.jhu.edu/conservatory/admissions/tips/doubledegree.html
Do you play an instrument? Is it important for you to continue that formally? Do you want schools with instrumental auditions for composers?
Do you envision yourself writing for orchestra or mainly small ensembles? Mainly tonal? Any interest in electroacoustic work? Ethnomusicology?
If you want a BM and also want a university, then you are looking for music schools or conservatories that are part of a university, is that right? There is also the possibility of a double degree, a BA and BM, or, in the case of Harvard and NEC, a BA and MM. And composers can also do a general music degree for a BA, major in something else entirely and take lessons, or do a BA in music with a composition strand, as at Brown. If you do a BA you can also double major, meaning music and, say, literature or French or history (or any other subject that is feasible with the intense music class scheduling).
If you major in music, no matter where you go and what degree you do, you will of course study theory, do solfege and dictation etc., study music history and analysis, ethnomusicology, composition and technology.
It’s good you are thinking about this already. Know that you can choose to keep many options open until this time next year, if you like. You can apply to conservatories and college, double degree programs, a range of choices, and decide at the end of April 2017. Lots can change over the next year.
From the work you have done so far, and the tastes you are expressing, you do not sound that interested in experimental work right now. You have not done any electroacoustic work. Your current tastes might guide your choices, but remember that you will be developing over the next 4 years, sometimes in surprising ways.
I have always felt the best criterion for choosing a composition program is diversity, and individuality, of styles. Particularly at the undergrad level. It just seems to be a sign of artistic freedom and respect. I don’t know if you can listen to student works or attend concerts.
I personally would not worry too much about a backup right now. I mean, study what you are interested in. If that is mainly music, concentrate on it, by all means. If you have other interests, pursue them too. For career purposes, or for a future “day job” (!) you can do education and outreach work while in school, volunteer, intern or work for music organizations (skills translate to other fields, especially the non-profit world). This 4 years is a time when you can explore and think about things- I really believe that. (It helps to go to a school that doesn’t have loans!)
We can give you more specific info. BM’s at stand alone and university conservatories/music schools: Juilliard, Curtis, NEC, Manhattan, Mannes, Eastman, Blair, Oberlin, Lawrence, Bard, Indiana, Peabody, Boston Conservatory, BU, Berklee (merged with BoCo), CIM, CCM, Rice, Ithaca, Rutgers Mason Gross, Temple Boyer, Hartt, U.of North Texas, SUNY Purchase and other SUNY’s, NYU, USC, UCLA, University of Puget Sound, Cal Arts, McGill Schulich, Northwestern Bienen, many more.
I believe most state universities offer BM’s.
For double degrees, Oberlin, Bard, Lawrence, Tufts/NEC, Harvard/NEC, Peabody/Hopkins, Eastman/Rochester, also many more.
For a BA there are countless choices, Ivies as mentioned above, universities (U. of Chicago is one), liberal arts schools, including small places like Sarah Lawrence or Bennington.
For grad school, you need a portfolio of work. There are many many ways to accomplish that. You can study music- and composition- in whatever way you want to as an undergrad, and still have what you need to apply to grad schools.
Oh- and if there is a school your really like and there are no concerts for undergrad composers, make them possible yourself. In general, there are many paths to getting what you need as an undergrad composer and as you already know, some of those won’t even be in/at your school.
Summer programs are great- glad you are going to one this summer.