Josh -
I have already said that I have boundaries too. There are some people that can listen to much more than I can. I recognize where God has given me convictions and I do not try and push the boundaries of those convictions.
When I listen to music I know that God is sovereign and far more powerful than Satan; I also know that because I am His he will give me convictions so that I know what my boundaries are. There are certain things that I do not listen to because they put my mind in the wrong place. I use wisdom (i.e. the fear of the Lord and at the same time, my faith in His spirit) to know what I should and shouldn't listen to.
I am sorry if this comes off as prideful. I actually say this with complete humility in my heart: I don't expect everyone else to have the same convictions as I do. Some people can handle more, some less. That's not good or bad, it's just God telling us what we can and cannot handle. People need to be discerning no matter what they listen to. If they listen to secular music, then they should filter that message through scripture, test the different ideas that it presents and then get rid of the bad and cling to the good. If people listen to Christian music, they should constantly, consciously, and rigorously be ensuring that the ideas presented are biblically and theologically sound. (I'm sure some of the music that I like that is by christian artists would probably offend you. Thus, you don't see me recommending these bands or artists to you, do you?) If a Christian is content to listen to music ignorantly without using any discernment at all, taking in everything, and accepting it as truth, then they should not be listening to music at all. And that is not just music; that goes for everything. Christians need to be discerning in everything.
I always talk about secular Gangstar rap and secular heavy metal and you always take my posts and compare it to music like Celine Dion or a classical symphony.
The only reason I bring other genres up is because music is music. Unless you have a special Bible that says that rap and metal are wrong, you are trying to enforce an extrabiblical conviction on other people who may not have that conviction. I don't think it's the genre that matters, so much as it is the message. If I took the words to one of the rappers that you are against and sang them with a symphony playing in the background, would that make it morally better or worse? No. Blanket statements and generalizations don't help your argument.
Tell me how God is glorified through Slayer and Eminem?
I don't listen to either of them, so I don't know enough to say. Although I will say this, if Christians understood art better, then this whole arguement would be a moot point. But as it is right now, Christian music is nothing to be proud of (with very few exceptions). I think that it is much more important for us to find Christian artists who have some integrity and authentic musicianship, rather than complaining because some band doesn't say words that we like or sings about this or that. If christian's music (that is Christian's [possesive] music and not Christian music) was checked more rigorously for originality and creativity, then I could understand why people would rather listen to some artists over other christian artists. But for now, why would people want to listen to Christian music, when it is just derivative parody acts of the secular bands that they preach against?