Not knowing what your religious beliefs are, I hesitate to mention that the Christian Rock music genre has a very large selection of music that has the beats that my 12 year old loves along with lyrics that are not promoting sex and violence.
That said, DS loves to listen to any and all music from Gregorian chants, folk music and classical to what you hear on today's pop music radio stations. Country, Jazz, Classic Rock (Anyone else find it odd that the 80's music is now in this catagory?). I mean he loves everything. So far our attitude has been to make sure he asks about lyrics he doesn't understand. When we hear some of them, we ask him what he thinks the song means. This has been pretty good for keeping the lines of communication open. We do tell him sometimes that the lyrics are not appropriate to his age and that there are adult themes that we prefer him not to worry about right now. Usually, then he changes the radio station when those songs come on.
But, on the positive side, knowing the current music scene does give him some social confidence at school.
Good luck! We are just starting down the Teenage path with DS. It is going to be a rough road...