Rap is of the devil. Screamo is absolutely evil, even if it is so overtly Christian that it makes you want to puke. Rock is only acceptable when it is oozing with a good message, though if it borders on loud it's out too. Contemporary Christian is not even a subject of discussion, because of course it's okay. Music from the 70's and 80's is guaranteed to be annoying, and most of the time you can't tell if it's a girl or guy singing. Popular new music will for sure be run into the ground, so even if you liked it at first, you will groan and change the channel as soon as the song starts for the millionth time.
Country music doesn't have to be as clean as any other genre, just because it's country. You could listen to songs about drinking, smoking, cussing, and women all day long and no one will say a word because that's just the culture. Heaven forbid we would listen to something like that of another genre though! There are a few songs that are not appropriate, but they are usually out-right horrible.
However, if you are listening to bluegrass, then anything goes. Songs, such as ones about how wonderful corn liquor is, that would normally be looked down upon at other times, are now turned up to their loudest volume as little children dance away. And no one says a word. There is no such thing as an inappropriate bluegrass song.
Disclaimer: This is all in fun... I do not actually mean any of this. By all means, blast that Christian screamo, and please do not listen to bluegrass songs about drinking. Thank you.