I have always been one short of words. I
in short of words
Grammatically, I don't see a lot of errors~~but I am not a native speaker either, sorry I cannot help more.
I like you topic that how music helped you express your feeling! This is a good essay overall.
Just a few suggestions:
1. in the first paragraph, it would be better if you could give some examples of your favorite pieces. I would suggest to put them after "One combination of notes can say so many things". e.g. the XXX 's light and joyful rhythm could instantly brings me back to the precious childhood memory, while the solemn and sentimental XXX turns me to a heart-broken to grief his lost love.
something like that. I am not a good writer, but I hope you understand what I mean.
2. I wouldn't say something like "I have always been one short of words. I never really had a way of saying what I felt. " you don't want to show the admission officers that you are not a good communicator. I suggest you could put words like "sometimes" there to make it less evident.