when you have a rhyme in a poem for me It has a better flow to the words but you can still have a flow even when the poem doesn't rhyme.
I actually like to make them rhyme. Here's just a short sample of something that just comes to mind
Something just popped into my head
a song, poem or even something I've read
In a book or on a piece of paper
given by a friend or spouse
definitely not from a church mouse
something else just popped in my head
can't wait to know what it said
just looking at the sheet
wondering who's the next one to meet
does that help I'm sure it will.