Forget about terms like “spikes”. That is based on mistaken ideas as to what “elite” colleges are looking for. Aside from a great academics, they want to see “excellence” in other realms as well. When a kid has a single focus, or is engaged in an EC which is time intensive, it can be described as a “spike”. It isn’t, really, unless the kid is soooooo good at that one thing, that “elite” colleges think that they will be a good addition just because of that, like, say, a kid who is an absolute genius at math, and has won multiple top national and international awards, but is a B student in everything else.
That is not the general case, though. In general, “elite” colleges like seeing students who are, overall, very accomplished academically, and have multiple interests outside of academia. These colleges also want to see some evidence of particular excellence, so having some awards or high level accomplishments is also part of the package that these colleges like to see. Since time is limited, it is rare that a student has such awards of accomplishments in more than one or two fields.
Playing music for 12 years is one of those ECs that interest selective colleges. Moreover, since you are evidently passionate about music, it should be up front and center in you application. A publication in the Concord Review is another good accomplishment, and will add to your overall profile.
Neither, on their own, will cause AOs at Harvard to say “we gotta have THAT applicant”.
As @thumper1 asks - why? Moreover, “the Ivies” are eight very different colleges with different strengths and different characters, which are only similar in that they are private (mostly), in the NE, expensive, have low acceptance rates, and belong to the same athletic conference. Oh, and they have “prestige”.
I mean, what do you want to study? What are you looking for in a college, aside from “prestige”, living in the NE, paying a lot of money, and being part of the Ivy League athletic conference? What do you think that you need from a college?
Moreover, since the vast majority of unhooked applicants, even the most qualified ones, are not accepted to any of the Ivies, what colleges are you looking at as the colleges which you will, realistically, most likely attend?