Technically, all lyrics are some sort of poetry. Granted, in order to have some success of sorts, usually poetry must be good. Lyrics could got either away. But in poetry, one of my favorite things is noticing when grammar plays a major role in the meaning or the grammar changes, resulting in new meaning.
Examples: The Lake Isle of Innisfree by William Butler Yeats. The sudden change from future to present suggests that the speaker has arrived at Innisfree over the course of speaking in the poem, implying that Innisfree is not a distant, physical place that one must travel to, but instead an inner place of nostalgia and ideals that comes to oneself at the thought of the past.
Joni Mitchell, one of my favorite songwriters ever, who wrote one of my favorite songs ever, “Chelsea Morning” is the queen of grammatically significant songs. In “Chelsea Morning,” the lover singing suggests “oh won’t you stay/we’ll put on the day/we’ll talk in present tenses” showing that present tense is less intimidating, at least to lovers living in the present. Why would they plan anything when they already have milk and oranges and honey.
In Tom Petty’s “American Girl,” he recounts a story of a girl who herself is remembering a guy she knew someone once. The chorus emphasizes this by being in the present tense, while the rest of the song is in the past tense. By being in the present tense, it allows for ambiguity concerning who is telling the girl to “make it last all night.” It could be either the man she is remembering or the man who is telling her story, and that could change the meaning of how she took the advice. Did she take it from the remembered man and fail at it or has she yet to fully comprehend/hear it from her story-teller?
Those are my two favorite examples, and I’m sure there are countless others.
EDIT: Thought of another one. “I and Love and You” by the Avett Brothers. That’s totally a perfect example of anaphora used for emphasis. I had to share. It is pretty obvious which one is a grammar dork. Well, probably me, and you for reading this far.