I like the way it's set up chronologically here, in terms of rise to popularity (first modern art music, 1950's and 60's, then punk, 1970's, then thrash and death, 1980's, then emo and post-hardcore, 1990's and 2000's). Moving emo and such into the Punk section would break that up... As for grindcore, doesn't really matter to me where it is, as long as the sources I dug up don't get removed.