Dr Dre is a professional poet and a very successful one by any standard. His whole stock-in-trade was American urban colloquialisms most of which can be traced back to English rural and working class and predate the colonization of the Americas. The early development of English "prestige grammar" and word usage dates back to the court of William the Conqueror and the reintroduction of romance linguistic influence on Anglo-Saxon English that lead to the development of Middle English by the 13th Century. What you understand as English "prestige grammar" today is a moving target, consistently evolving but still full of contradictions and single-case rules. Many popular European languages today have been modified to exclude these linguistic anomalies, making them more consistent, less error prone and easier to learn. I expect the same thing will be done to the English language over the next century.