I want to know the answer to the following question:
Along with teen pop, dance and hard rock, what form of music is typically not heard on AC radio?
All the background I'm provided with is that "A common practice in recent years is that many adult contemporary stations play less newer music because they also give ample airtime to hits of the past, so the de-emphasis on new songs slows the progression of the AC chart.". Is that enough to answer the question?