Read the excerpt from the poem “Barbara Frietchie.” Up from the meadows rich with corn, Clear in the cool September morn, The clustered spires of Frederick stand Green-walled by the hills of Maryland. What makes these rhyming couplets? The words in each line present a complete thought. The words “rich,” “cool,” and “green-walled” describe the setting. The words “clear” and “cool” start with the same letter. The words at the end of each set sound alike.