As those with their ears glued to the Internet grapevine may already be aware, Eminem and Royce Da 5'9” are Living Proof. Proof of... what, exactly? Well, you can take your pick: proof that Motown is a breeding ground for dope emcees, proof that artistic chemistry trumps pointless beef, proof that hard-hitting street music is alive and well... In any case, this unreleased joint, leaked to the 'net earlier this week but presented here in its final, tagless form, is proof that prior collaborations Bad Meets Evil and Session One (with Slaughterhouse) weren't flukes. Here, a currently-unknown beatsmith's hard-nosed bass-string arrangement sets the stage for the Detroit representatives' lyrically bruising back-and-forth. Shady's rhymes are even more aggressive, and provocative than usual, and Royce's unhinged imagery (“You might as well have cut the embryo out of my mama and played catch with the baby with AKs, with baby bayonets.”) is no less jaw-dropping. Who comes out ahead? It would take hours for me to decide, so I'll let y'all do the honors – or, if you prefer, just sit back and bask in the dopeness.