There is no one right way to write an essay. My older daughter wrote hers about expository writing, using expository writing to do so, and led around to her discovery of and passion for feminism. There was no anecdote, and she did quite well in college admissions, probably because of her essay, which was out of the box.
That said, there are some things a successful essay has to accomplish – essentially, it’s a way to market yourself to adcoms. A good essay hooks the reader’s interest early. This is most often done by telling a story, but in D1’s case I imagine the interest came from wondering how on earth she was going to turn her intro into into a college essay.
The essay should make the reader get a little bit of a sense of you as a person – specifically, something about how you think. Of course, the idea that you can condense who you are into a 600-word essay is pure nonsense, but it’s the only part of your application that gives adcoms the illusion that they know something personal about you. (Why this is necessary or appropriate is a whole other discussion.)
The essay should make it clear that you have something to contribute to a college community – i.e., you have interests that will enrich the lives of your classmates and you don’t plan to spend 4 years skipping classes and surfing the web in your room. Clearly your interest in music fulfills this.
And finally, the best essays make the reader like the writer.
Accomplishing all this is a tall order but it’s do-able, and there are a million ways to do it.
Finally-- please, please, please get feedback from a trusted adult. It is often hard to tell how your writing comes across to others, and most people have to work through multiple drafts. I have been astonished at how many people write self-sabotaging essays. One essay draft I read included a confession of how the writer had failed to live up to his potential in high school-- not a good way to sell strangers on admitting you to their college!
One last thought – your essay doesn’t have to be perfect, and most essays neither help nor harm college applications. But if you write a really good (or bad) essay, it can make a real difference in your chances for admission. I wish you luck!