One could apply that to any endeavour – reading, eating, drawing, etc.
Must one only read the Bible, the Church Doctors, and Lives of the Saints? Can one read “secular” literature? Is “entertainment” evil? How much is one allowed to “enjoy” something?
Sometimes, listening to a song is the audio version of eating a cookie. Normally I eat to fuel my body, to keep myself healthy, or as a social exercise to interact with family and friends (all Good, I reckon). Sometimes, though, I just want a cookie.
Same with music. I love the old hymns, have only recently discovered polyphony, etc. But sometimes…you just ain’t seen n-n-n-nuthin’ yet.
I think if the music is not in and of itself immoral (lyrics etc), it is the equivalent of a cookie. Have a few, enjoy, but don’t make a meal of them.
Moderation. Just don’t be a slave to any of your appetites – except your appetite for God.