Every good rapper has a vault full of dope tracks that never saw the light of day. The latest emcee to shoot an unreleased song from his arsenal is Yasiin Bey (formerly known as Mos Def). Bey hit the stage at Chicago's The Shrine, and performed "The Light is Not Afraid of the Dark," a song produced by Kanye West. At least six years old, the song was slated to be included on Bey's 2006 album, "True Magic." Check out his flow over the bass-heavy beat in the video above, which also features a short interview.