After Saba’s appearance on Chance the Rapper’s “Angels” and its accompanying performance on The Late Show with Stephen Colbert, the Chicago upstart has been getting a lot of attention lately. Tonight, he’s shows off his lyrical fierceness on “Soap Box.” Produced by him and Phoelix, he takes an edgier approach, methodically floating over the raw production. It also showcases his singing, as the beat smooths out with a soulful backdrop. “Soap box on my stage, about to start a mosh pit,” he raps, and that’s just one of many lines that stick. Listen below.