Here is an article from Cambridge English blog on using songs to teach English.
Why use songs?
Songs provide good listening practice for teenage learners – but with a difference. Songs can tell stories, and convey emotions. Music can set the scene or provide a change of mood. You could use a song at the beginning or end of a class, or build a whole lesson around it, its meaning and the singer or band.
In terms of language learning, the rhyme and rhythm of songs are great for pronunciation work. Songs often use repetition of vocabulary or a grammar structure and can be used to help learners ‘notice’ language use, guess the meaning of words or phrases from the context, and lead into speaking or writing activities.
All of these are useful skills for improving students’ general level of English as well as to prepare for an exam. Students often enjoy listening to songs in English and understanding them can be motivational.