Mastodon: Brent Hinds (vocals, guitar); Troy Sanders (vocals, bass instrument); Bill Kelliher (guitar); Br„nn Dailor (drums).

Mastodon's sound is challenging to pin down because it doesn't fit comfortably into any one genre, being more of a bastardized amalgam of several other styles -- and again, not easy ones to pinpoint. Picture In the Eyes of God-era Today Is the Day (Mastodon members Brian Dailor and Bill Kellihor were in that band, after all) butting heads with the more technically demanding school of Relapse-style hardcore/metalcore (e.g., Dillinger Escape Plan or Burnt by the Sun, although Mastodon is much less hyper). Then add in detours into countryish rock (check out the intro to "Battle at Sea") and a few spy-thriller riffs (see the end of that same song), and top it off with roaring, semi-distorted vocals and a whirlwind-evoking, almost jazz-like drumming style. Brian Dailor, the drummer, is the real driving force behind this band -- he's all over the place, constantly filling in the cracks with drum rolls and offbeat accents. He has plenty of tricky time signatures and tempo changeups to keep himself challenged, but the songs are also well-structured and avoid getting technical just for the sake of it. Based on this release, the band will need to raise their riff-writing skills up a notch to really get into the elite territory of the above-mentioned bands, but in any case this EP suggests they do have lots of potential. ~ William York