I find talking about the music good, as it slips in some good discussion on technique.
I use a song by Rage against the Machine in module C, and I'll often comment on the raw and powerful nature of the music itself in how it conveys such potent language and social commentary.
But, like any discussion on technique, you've got to make sure it's relevant to what you're trying to say. Throwing it in at random won't get you anywhere!