Write out the lyrics of the song, but make about 20 mistakes e.g. change the tense, write an opposite or synonym instead of the correct word. The students listen.
The first time ask them to underline the words that are different and the second (or third) time actually write what they hear above the word or phrase that is wrong.
After each hearing they can check with each other – in a mixed ability classroom this ensures no-one is left behind and gets demotivated.
After they have checked that they got the right words, ask them to go through and see if the mistakes were words or phrases that were the same, similar or opposite in meaning: a good focus on vocabulary and/or grammar.