We're goint to have an entry for 2 slightly overlapping genres, both who fall just outside of the big rock umbrella. Ska is the upbeat reggae style that often crossover into rock and punk. Punk is stripped down rock with plenty of attitude. There's just enough of both in the brony community to warrant a highlight on this page. Whether fun or angry you'll find plenty of energy in both.
Check out these artists for Ska and these for Punk who specialize in this style of music.
Feel free to recommend some artists not included in here (these artists specialize in it) or include up to 10 of your favorite acoustic tracks in the comments section (for an eventual best of countdown).