<p>I decided to play the piano for the fine arts supplement, but on the common app, should the category I choose be keyboard, or percussion?</p>
<p>Uhh, keyboard…</p>
<p>Hm… that’s actually a good question, since piano is categorized as a percussion instrument. If you feel uncertain, you definitely should call the Stanford office. They’re always willing to help (I called them about a question about time limit and got it handled within a minute) 
but most likely, it’s keyboard</p>