Besides automatization, there is also a linguistic reason for using songs in the classroom. Some songs are excellent examples of colloquial English, that is, the language of informal conversation.
Studies found that music is often the major source of English outside of the classroom. The exposure to authentic English is an important factor in promoting language learning. It relates directly to both the affective filter and automaticity. If students are exposed to songs which they enjoy, more learning is likely to occur since they may seek out the music outside of the classroom. The repetitive style of songs then helps to promote automatization of speaking.