What kind of common app essay looks better or is more unique?

Answered

From the perspective of someone who's worked with... at this point something like 100-150 students on their essays, both of these are valid subjects for a Common/Coalition App essay, but they do both have some drawbacks that you'll need to weigh. Which one would appeal "better" to an admissions officer depends entirely on how they're written—and that's how it is with most essay ideas. It's rare you'll find an idea that would actually be disqualifying if written well, and no topic is going to put you over the top solely on its own. Your approach is what's really important.

First, I'm going to disagree with the comments already here and say that the idea of writing about your dad's death and its effect on you has a lot of potential, and could be an extremely effective Common App essay. For what it's worth, the idea that you can't write about things like deaths in the family are not so much hard and fast rules as guidelines for the average student to follow—most people, by definition, are not going to be able to write a strong essay because most people are not going to have the experiences you've had. If you have meaningful things to say surrounding that experience—and it sounds like you do—there are risks to writing that essay for sure but also ways to do it well.

Namely, it can't just be an essay on "this is what I had to do when I was 6 years old"—it has to have relevance to the person you are right now, the way you look at the world, your values, and how you approach your future goals. You shouldn't spend more than say a third of the essay narrating your experiences from the past—the majority of the essays should (in a figurative, not literal sense), be in the present tense. If you can do that effectively, and make the essay about the kind of person you've had to become when faced with a tragedy like that, it could be a really strong essay.

For the other idea, it has a lower floor (easier to write an essay that will basically work) but probably a lower ceiling (it would be really hard for it to match the emotional resonance of the other idea). If you're uncertain of how to approach writing about your dad's death, I would use the time that you have to try and draft this essay first and see how it turns out. A couple of notes—again you should make sure the essay relates in some way to your ideals and values (it sounds like it already does), and, if possible, how those might apply to your goals. That doesn't mean what you plan to study necessarily, but more so the values and goals you hope to live through and carry out in your life at large.

I would also try to make sure, in that one, that your focus remains on you and not on the music that you're writing about. A common pitfall when you choose to write about art or music or even politics and activism—i.e. topics that don't implicitly relate back to you (as opposed to a topic like the first one)—is that it can become easy to write an essay about those topics and not about yourself. So if it becomes an essay about 60s and 70s rock-n-roll where you're more of a side character than the main focus—that won't be very effective. But if you're able to use that music as a lens or a window to, again, your own goals and values, then it could work very well.

I hope that helps. The basic rule, in reality, is that essay subjects are rarely inherently bad or good. 90% of a college essay is how you write it, and how you parlay that topic into a meaningful narrative about yourself.