You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Adult_contemporary_music

Context:
AC radio stations may play mainstream music, but they will exclude hip hop, dance tracks, hard rock, and some forms of teen pop, as they are less popular amongst the target demographic of these radio stations, which is intended for an adult audience. AC radio often targets the 25–44 age group, the demographic that has received the most attention from advertisers since the 1960s. 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.

Question:
Along with teen pop, dance and hard rock, what form of music is typically not heard on AC radio?

hip hop