Rabbi: Bava Basra 91B Rav Yochanan.
Also in the opposite direction we have Chalov Stam.
Mz. Postsem (or anyone else) should not listen to anything that affects their soul the wrong way. Having someone else monitor what may or may not be heard sounds Orwillian to me (we are at war with eastasia and we have always been at war with eastasia, and anyone who says we have not been at war with eastasia will be re-educated).
It may be a better idea to personally avoid certain music, and have the Gedolim (for each area, what works for E”Y does not work for the USA (such as ballplaying)) give clear guidelines as to what is allowed and not, and let the people decide what they do. After all, this is a hashkafa issue, not a halachic one.