Discuss the structure of the poem as well as formal elementes(Stanza,rhyme,figure of speech(Expand on the main topic concepts as well as the semantic field in this poem?

There are a number of poems in this collection, and it would take an essay to give you all the information you've asked for. You might want to begin your research with gradesaver's study guide. It will help you formulate an answer to the above questions. I have provided the dorect link below.

http://www.gradesaver.com/songs-of-innocence-and-of-experience/study-guide/section19/