I have heard that satan was the music leader as well MrWonder.
I think the thing is whether the words glorify God. When I lived in Atlanta I listened to a Christian radio station that refused to play songs that didnt' mention God and were just considered Christian by many because of who sung them. Their stance was that they were on air to glorify God and not "artists". I loved the station because it meant that it was usually praise music or something like that playing. I like contemporary Christian music; but, not necessarily just the rocky non-God lyrics songs. I prefer it to have God in it; but, that is just my personal preference.
I have been to Third Day concerts and the like and have noticed that they do all take the time to present the gospel and share their testimony. I do question the lyrics that don't mention God because you really cannot tell they are Christians by the words. I tend not to listen to much of that kind of stuff.