This is my conviction and I can back it up with scriptures if needs be. Believers and followers of Christ should not be indulging in rap, pop, r&b, hip hop, etc. It is impossible to get a clean thing out of an unclean thing (Job 14:4). The types of music listed above are unclean. If we carefully study the history of these music it will point to man and NOT Christ. Observe the gestures of the artists during a performance. They usually point to "self" and NOT Christ. Scripture is fulfilled: (2 Corinthians 11:14 (KJV) And no marvel; for Satan himself is transformed into an angel of light.
It might seem ok to listen to these types of music because of the words but it is NOT ok. We need to carefully study the origin and culture of these categories of music and observe where the glory is pointing. These categories of music bring pleasure to the flesh due to the beat.