http://pure.dswarmsikhttkg7jgsoyfiqpj3ighupfrvuz5ri3lu5q2dlqyrpgk7ad.onion/posts/a-draft-of-the-concept-of-poetry.html
I even can say they're not instances, they are poetry itself, stands together to form the ideal wholeness of Poetry.
To some extent the realm of music is broader and more exquisite, taking out one of the definitions of music, there's a high probability that poetry can be defined clearer in that definition.