I am planning to go to college with a BA or maybe a BFA in Theatre/Musical Theatre (most likely in a less competitive program, open to non-MT major if I can still get dance and vocal training.) I am wanting to double major in Music Composition(or Theory). I have played several instruments and can read music well, but I am not proficient enough to audition (especially since I am dedicating my time to my theatre auditions, and I am not a classically trained vocalist.) I have taken online and offline theory/composition classes, and want to continue this education in college with classes in music theory, music composition, orchestration, and conducting, and piano lessons. I know "most BA Music programs are non-audition), but I am having trouble finding one, or at least finding one at a school that still has a strong dance and theatre program. I do not have the best GPA, so Yale is off the table, but I have very high SAT scores. If not a major, are there any schools where I could take these types of classes as a non-major.
you could possibly take them at USC [U of Southern Calif] as a non music major. But if you want to double major, or minor in ANY are of Music, then you will HAVE to audition there.
Luther College in Iowa or St. Olaf in Minnesota would be good options
I may not be understanding your question so maybe you can clarify. Why are you having trouble finding schools that would allow a BA in music and theater?
If you want to study composition and theory, you can do that within a general music major, at many many colleges and universities. With no audition at all.
Some schools have a composition strand in the music major (Brown for example) but many don’t. You want to make sure that there are either lessons or small classes for composition, and chances to have pieces performed. Honestly, composers don’t even have to major in music.
I would choose a school based on size, location, academic and “vibe” and then look at theater and music course descriptions. Then look at the curriculum for each major with required courses. Be flexible in your thinking: as you said, there is much you can do even as a non-major.
And don’t forget extracurriculars. In schools without applied programs (non-conservatory, extracurricular theater and music become more important (and often have auditions once you attend.)
Besides double major, there is also major/minor and of course double degree. Have you read the Double Degree Dilemma essay closer to the top of this forum? It might be helpful.
Since you want dance and vocal training, and also want to do applied music, are you interested in a performance program rather than a BA? If so are you asking about BM programs that might have no audition?
If you are asking about BA programs with both theater and music, there are countless schools. You only need a general music major for theory/composition and the other areas you mentioned. These classes are offered at so many schools.
Remember that a BA will often mean distribution requirements and most always will mean 2/3-3/4 classes will not be in the area of your major. A school with fewer distribution requirements (Brown, Amherst, schools like Bennington etc. will afford more room for your many interests. You can also use electives. It is good to look at websites, and, what classes are required for the degree, and sort of plot things out.
One other thing: for grad school, composers need 3-4 piece for the portfolio. There are many ways to get there. Think about summer programs as well: many schools will fund them.
Good luck!