Romans 1:32 Although they know God's righteous decree that those who do such things deserve death, they not only continue to do these very things but also approve of those who practice them.
These artist are promotiong a "bad lifestyle" so it is sin (and trust me, I used to listen to rap and I know most of it is sin, please don't play the fool with God). If you are listening to it, you aprove of it. That's an undeniable fact.
Romans 2:8 But for those who are self-seeking and who reject the truth and follow evil, there will be wrath and anger.
Don't believe that not actually following their actions and not smoking, having premarital sex, or doing crime, etc. means your not following them. "For as he thinketh in his heart, so is he"(Proverbs 23:7) You think of these songs with approval when you listen to them happily.
1 Corinthians 13:6 Love does not delight in evil but rejoices with the truth.
This is self explanitory, but your are delighting in the evil message they are giving and are not showing love to God.
2 Thessalonians 2:12That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
You don't want to be damned do you. That is the key principal of this verse. So I suggest you stop filling your mind with those secular demonic messages. That is, if you really care about whether or not you are sinning and are not just looking for someone to approve your sin. I am not trying to be harsh, but if you know deep down inside you won't repent no matter what we tell you then stop wasting our time. I'm not saying your wasting our time, but if you know you love the music too much to repent, then you are.
(Jeremiah 42)
Like the person said in an earlier post..:
Finally, brothers, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any excellence, if there is anything worthy of praise, think about these things.