Grief and loss aren't something typically associated with horror-core specialists Slipknot, but when founding bassist Paul Gray died in 2010 they dedicated The Gray Chapter to their friend. Slipknot's first album in six years, it's both a eulogy and a means of moving on. "I don't want to get up, but I have to," sings Corey Taylor on the opener, "XIX." What follows is a blitzkrieg of a tribute.