This analysis misses the forest for the trees: modern pop music is all about stylistic and sonic innovation. Musical forms tend to evolve along certain parameters while holding others constant. In jazz and classic there has (historically) been a lot of exploration in harmony and melody, but the sonic palette has held steady over long periods of time. Pop music is the opposite.

In the world of rap music, the sonic innovation has been extreme. The meaning of a Public Enemey "song" cannot be assessed through this type of analysis.