When El-P began production work on Killer Mike’s jarring 2012 album R.A.P. Music, the two intricate-rhyming MCs formed an instant creative bond. "It was immediately just explosive," El-P told Rolling Stone last year. "Sometimes you just meet somebody who you've felt like you've known all your life. That's how me and Mike felt." The duo's creative partnership now continues: billed as Run the Jewels, the twosome recently wrapped recording on a split-bill collaborative LP – which they'll release for free – featuring guest spots from Big Boi and Prince Paul. They’re also set to hit the road together this July.