The smut they call "music" are effectively cult chants. This is fairly common in cults--and they dissuade people from listening to outside music (or for that matter, anything that comes from without). In the jokehovian witless cult, you will lose "privileges(??)" if you are caught listening to rap or heavy metal, and they have criteria that make other songs "bad". I have seen older rags from the 1970s and early '80s bashing funk, disco, and plain rock music as evil.
This is quite common in cults to restrict what you are allowed to listen to. But, as bad as the jokehovians are, I have heard of other cults that are even worse. Take a small cult called "the children of God". I have seen videos on that cult, and it is, believe it or not, even worse than the jokehovians in many aspects. They have a fast rule that one may not listen to "systemite" music, which leaves them only their own cult chants to listen to. And they cannot watch TV or movies (the jokehovians allow up to PG-13). They also do not take drugs of any kind (including aspirin for a headache) or even vitamins. Nor are they allowed to read anything not provided by the cult--so much for learning that foreign language).
Which doesn't make the jokehovian cult any better. Only that one can end up jumping out of the frying pan and into the fire if one is too hasty to join another religion.