Mos Def and Talib Kweli are Blackstar. The track, as Kweli alludes to in the opening verse, is based on the 'The Bluest Eye' by Toni Morrison. The book, among various themes, focuses on how the black communities standards of beauty, values and morals are set by white American society.
The "Nature of the Threat" is considered by many to be Ras Kass' magnum opus off of his debut album Soul On Ice. In it Ras Kass basically spits verses encyclopedia style documenting the evolution of man and the origins of racism.