In recent years, the old definition of rap music has slowly been changing with signs of a long lost era. Today, most rap is replaced by the generalization of hip-hop and R&B. This seems to be a trend that is not likely to go away soon, as politically correct voices make changes in how artists in the rap industry can express themselves in their songs. Just 10 years ago you would have been called crazy to say that there would be a time in the near future where artists were not allowed to express themselves in their music, or not allowed to use certain words or names to describe others.
Censorship is gaining more and more ground in the rap industry as political figures make direct ties of violence and "hostile" intent to rap artist's music. Think it can't happen? It already has.