The back-and-forth nature of the two-voice poem effectively expresses the differing viewpoints of the poem's subjects. The alternating verses show where perspectives contrast and where they align. Also, because two-voice poems often sound like a conversation between two people, they can be engaging to both read and listen to.
Poems for two voices typically have two columns. One person reads the words in the left column, and the other reads the words in the right column. The readers take turns reciting their parts except for when text appears on the same line -- those lines are read in unison.
A slight variation on the standard format uses three columns. The shared lines appear in the center column. Another format alternative is to color code the lines so that each reader chooses a particular color of text to recite.
Notable poet of the two-voice style, Paul Fleishman, won the Newberry Award for his book "Joyful Noise: Poems for Two Voices." David Harrison wrote a book of poetry for young children titled "Farmer's Garden: Poems for Two Voices." Stephanie Klose is known for "A Graduation Poem for Two."