OK, so I tend to think most college-bound kids should make a point of taking all of Physics, Chem, and Bio at the high school level at least once, regardless of intended major in college. I don’t think any of those has to be an AP, so good so far.
For selective college admissions, I tend to think it is a good baseline suggestion to take a natural science all four years. So, assuming you do all three of Physics, Chem, and Bio at the non-AP level, maybe you take one of those at the AP level as a senior. I also think you can do something like AP Environmental Science if you prefer. I would not count AP CSP, though–that is classified as a Math elective, and I agree.
But suppose you only want to do the three core science classes, and skip a fourth. Are you totally doomed for selective colleges? Of course not. But now you need to start checking what any colleges of interest actually say on the subject.
So what does Fordham say? Here you go:
https://www.fordham.edu/undergraduate-admission/apply/what-were-looking-for/academic-achievement-and-rigor/
OK, so they say a couple things of relevance.
First, they say they want you to challenge yourself, and then say APs are one way of showing you have challenged yourself at high schools that actually offer APs. Does this mean you need to take literally as many APs as you can? No. But if your school offers AP science classes, would it be a good idea to take at least one if you are applying to Fordham? Yeah, probably.
OK, then in terms of specific course breakdowns, they list:
On the plus side, this is implying you could do just three years of science. On the minus side, they don’t just leave it there, they say “3-4”.
My suggested interpretation of this sort of recommendation is you should probably do four UNLESS there is some obvious reason why you wanted to do something else. Like, for example, Arts kids might have transcripts crowded with advanced Arts electives, and in that context maybe just doing the basic three science classes make sense. If you were a CS or Engineering kid, maybe you would substitute CS or Engineering electives for a fourth year of science–although ideally, you would do both.
The basic problem I see with your plan is you are looking to do AP Music Theory or CSP, but then you are not planning to apply as a music or CS kid. I don’t think that is a problem if you can do that AND a fourth science class, but I would see it as potentially not quite the best plan if you are not doing a fourth science.
That being said, at the end of the day, how plausible is it that Fordham would want you as a kid with an AP science planned for senior year, but not as an otherwise identical kid with AP Music or CSP planned for senior year?
That’s such a narrow scenario that realistically, if you really wanted to take Music or CSP, then I would just go for it and not worry.
But if you are asking what would be optimal, and don’t feel strongly about wanting to take either Music or CSP, I would probably go ahead and think about a fourth science instead, preferably an AP.