The genre was extremely diverse stylistically, including subgenres such as gangsta rap and Hyphy. It contains a mix of music ranging between such genres as hip-hop/rap, krautrock, and electronic. Nas, Kool G Rap, Big Pun and Busta Rhymes. N.W.A is the group most frequently associated with the founding of gangsta rap. There is also debate about the causation between gangsta rap and violent behavior. Their music incorporated reggae, ska, dub, funk, rap, and rockabilly. Music critics commented on the freestyle rap. The lyrical themes of rap rock vary. It contained the first rap music record chart. He utilizes a fast-paced style of reciting poetic lyrics that is characteristic of rap music. This genre was called "disco rap". Although primarily instrumental, early electro utilized rap. Music grew fragmented and combined into subgenres such as house, goth, and rap metal. In the emo rap broke into the mainstream. The album incorporates elements of jazz rap and trap.