poetry doesn't necessarily rhyme, and even so most rap does rhyme to some extent, the rhyming schemes are just different than that of a sonnet. I'd look at rap if you want some words to experiment with in terms of rhyming. Hate to break it to you but rappers are arguably some of the best poets out there. A lot of them use tons of swears and shit but it's still poetry. The flow of rap is similar to that of poetry, and rap, similar to poetry, can hold so much meaning. Look up Grieves, listen to some of his songs, then listen again and focus on word choice, rhyming schemes and metaphorical meanings. Stuff like that is incredibly difficult to write, and every word is carefully chosen to add to the feel of the song. This is also true in poetry.
I may have seemed like a dick before, but trust me i was serious that rap contains many elements of poetry that are absolutely necessary in writing a good sonnet, poem or song for that matter.
pretty interesting 6 word memoir would be "Lost dog, please keep if found."
