I don’t love the terminology of “spikes”, but generally the whole point of looking at ECs is that residential colleges have all sorts of cherished student activities, indeed it is a big part of being an attractive college, and they need a constant flow of new students to refresh those activities as other students graduate.
And various activities need musicians. So even if you are not going to be a Music major, if they think you might be a significant contributor to one or more important activities, that will be a helpful sort of EC.
But aside from that general observation, from what I have read it then gets tricky to gauge how much it will help. Like at some prominent colleges, even a lot of the non-major music kids might basically have conservatory-level talent, or near, and indeed they might send recordings and such to a musical director of some sort to evaluate. And so getting much relative benefit at those colleges will require that level of demonstrated talent, and you may not necessarily know if the person who does the evaluation will decide they actually want to try to get you.
But other colleges might have a lot of activities where the talent expectation is lower. But others might not have as much in terms of musical activities at all. And so on.
So yes, as a general answer, demonstrated musical talent/dedication could be very helpful in some circumstances, but as usual it can be tricky to predict exactly which colleges will see it as helpful, but with some careful investigation you might shade the odds in your favor by choosing schools more likely to be looking for musicians like you to fill out their activities.