Slaughterhouse is a rap supergroup comprised of four of hip-hop’s most respected but perennially overlooked MCs. At different points over the past ten years, Crooked I, Joe Budden, Joell Ortiz and Royce da 5’9” have been poised to break through, but mass recognition has evaded them every time. They wisely decided to join forces, and the group’s eponymous debut upholds a branch of East Coast rhyme science that has been almost entirely obscured by the dominance of the Dirty South. While groups like Wu-Tang have stayed relevant by adhering to a signature sonic scheme, Slaughterhouse is strictly about the lyrics and the attitude. Like a basketball team that chooses to stick with the time-honored tactics of good plays and fundamentals, the album is both an exhibit of awesome skill and a manifesto from a group of men with serious chips on their shoulders. The key track is the roiling “Salute,” which features verses that act as resumes — or memorials — delivered over an instrumental of weeping funk.