The Question and Answer section for Langston Hughes: Poems is a great resource to ask questions, find answers, and discuss the novel.
I'm sorry, additional information is required in order to answer your question. Which of Hughes' poems are you referring to?
I think that a rhyme scheme would change the sincerity and realism of the poem. Rhyme schemes, in my opinion, tend to lighten the tone and mood.
What is your question here?