Now in its third season, this smorgasbord of all things death metal proudly bills itself as "the most extreme tour of the year." Hey, we ain't arguing. When you put together a lineup that includes Dying Fetus, Decrepit Birth, Winds of Plague, Cattle Decapitation, and bunch of other bands that sound like they were named by a hallucinating medical intern, it's sort of like drawing a line in the sand, you know? And who's gonna cross it? The Warped Tour? Pffft. You think those goody-goodies could ever muster the stones to book a band like Cephalic Carnage? No way. If you want positive energy and intelligible lyrics, go see Jimmy Eat World. If you want foaming rage and totally sick blast beats, followed by a sublime sense of doom and emptiness, you bust out the Summer Slaughter Tour. It's a simple matter of taste. This year, there are two headliners: Suffocation, a seminal death-metal outfit widely credited with inventing the genre's signature "death growl," and Necrophagist, a high-revving German foursome whose debut album was named Onset of Putrefaction. Whether you find that fact to be awesome or awesomely asinine, one thing's for sure: It's totally freaking extreme.