On this date in 1999, Rapper/actor/social activist Yasiin Bey, who was formally recognized by the Hip Hop world as Mos Def, released his first solo album, Black On Both Sides on the Rawkus/Columbia imprint. On his debut album following the Black Star album with Talib Kweli, Mos Def kept it all the way Brooklyn, with his lyrical gymnastics laced with …