Asker, you absolutely should be able to ask questions about song lyrics here. Alas, I can't guarantee you won't get the kinds of negative answers you anticipate – the kinds of negative answers you see here.
I am generally appalled by the responses you've gotten here, which mostly seem to come from a deep place of ignorance about both poetry and about vernacular and dialectic English.
That's a song and for this type of English anything is possible and "correct", so accept it.
Is so profoundly ignorant and wrong I am at a loss for how to address it, but to condemn it in the strongest possible terms.
The English in use in poetry is not "anything goes". Poetic license is a thing, but it cannot exceed the capacity of English speakers' ability to decode it into meaning or it fails as a poem.
The claim that "anything" can happen in poetry and therefore poetic usage of English is outside of rational analysis or comprehension – or explanation – is characteristic of people who hate and fear poetry. Such claims are expressions of intimidation and antipathy. They have marked out a part of the Commonwealth of Letters "terra incognita", and drawn a dragon on the map.
The irony is that it is in poetry and other verse forms such as song lyrics that the English language learner is most likely to encounter some of the rarer, yet still technically correct, grammatical forms. Such unusual verbal gyrations are occasioned precisely by the need to plant feet (and phonemes) in strict formal structures or express meaning through shaped emphasis. "I will be on the opposite shore" is more conventional, but "I on the opposite shore will be" is not at all incorrect, and when Longfellow employed it, it got him both a rhyme to "free" in the previous line and continued a rhythm suggestive of the gallop of a horse, which considering it's in a poem about a famous horse ride is probably not accidental.
In rap, some of the variation one observes from standard prescribed English is that it's typically in AAVE. Sometimes the answer is "Oh, this is in AAVE, which has this other rule...." I expect most answerers here are simply unfamiliar with the formal rules of AAVE, and aren't in any position to answer such questions. That doesn't mean those questions don't belong here. It means we need a deeper bench of answerers, with broader knowledge of the many variants of English that askers might bring up.