"As the songs leaves their tongues"

You have a grammatical mistake here with "leaves"..you should change it to leave.

"There is little doubt"

shouldn't be an "a" before the word "little" ??
I hope I'm not hallucinating.

"That there is no such thing a goodbye"
you meant "as" instead of "a goodbye",didn't you?.

you somehow focused on the rhyme too much that some parts of the poem lost their internal meanings.
over all..the idea of the piece was good.
you just need to focus on the vocab and the rhyme more

Write on :]