Beat poetry such as made popular in the 60s by homosexual activist Alan Ginsberg, combined with street-level noodling with record-players, combined with elaborate multi-layered/wall-of-sound production (over-production) derived from the work of people like George Martin and Phil Spector (before he went insane).

Rappers/hip-hop people like to strut around pretending to themselves that their "art" is wholly original and fresh, when in reality it is utterly and completely derivative in every way. 

Simply overlay the "poetry" of people who have nothing good or important to say, with sophisticated studio recording sampling techniques and voila! There it is. 

The basic structure of the lyrics is similar to the "story-telling" found in the ancient oral traditions of the most primitive cultures. Also evident in Civil War era slave -fantasies of the old African hero Johnny Congeroo - the mythical black Superman deriving from the oral traditions of African tribal-lore. In a word, colorful lies inventing heroes who in actuality did not exist. 

The Johnny Congeroo character is similar to the Paul Bunyan character from early settler-days, only in a black cultural setting.