Perhaps not surprisingly, listening abilities depend on rhythms in the brain. If your students aren't good listeners, perhaps it's because there's not enough rhythmic poetry in their lives. And they're not reading it aloud enough.
Does this not also raise some questions along the lines Plato raised? Might this not suggest there are in fact kinds of music good for you and kinds bad for you? That there are kinds of music whose rhythms help you listen/pay attention, and those whose rhythms make it harder to listen/pay attention?
Also, there is now good research on why people prefer harmony. (HT: Lynne Kiesling)