how to include elaboration on ECs in additional info

<p>How common is it to elaborate on extracurriculars in the additional information section? None of the guidance counselors at my school know anything about the common app. There's a few activities I'd like to talk about more, particularly my involvement in music. Is this the point of the EC short essay? I'm not sure if that's meant to be just a more descriptive recount of the EC or an actual essay.</p>