Awhile back I found a wonderful book called, Three Genres, The Writing of Poetry, Fiction, and Drama, by the novelist and short story writer, Stephen Minot. So far, I'm only partway through the first section on poetry. But right away I was struck by the similar characteristics for good poetry and good picture books.
Minot listed four major characteristics of poetry: length of line; sound devices, rhythmical patterns, and compression of statement.
Length of line, he suggests, is essential to the poetry art form. It may be anything from the visual shape created by how lines are arranged, to simply how a line ending emphasizes a concept or word: Words are arranged for a special effect on the reader that would be lost if the lines were altered in any way. In picture books, too, length of line matters for the above reasons, as well as the fact that lines must telegraph meaning in a form quickly and easily grasped by the listening child. Every word counts in a picture book. It's placed where it is for a reason.
Sound devices in poetry include rhyme (when line ends in the same sound), alliteration (when words begin with the same sound), assonance or consonance (when vowels or consonants within lines echo each other), and onomatopoeia (when a word sounds like what it describes, such as "buzz" or "hiss" -- Minor's examples). All of these sound systems work to advantage in picture books. Familiar examples of rhyme, of course, are found in various editions of Mother Goose Rhymes, but Karma Wilson uses rhyme beautifully, as well as assonance and consonance in The Cow Loves Cookies. In Yannick Murphy's The Cold Water Witch, onomatopoeia is used to great effect when the witch wakes the little girl up by calling, "Wooooooooo!"
Rythmical patterns relate to stressed and unstressed syllables (what readers may think of as "the beat"). Rhythm can also be achieved by repetition of lines. Both the beat and repetition are familiar devices used in picture books, from Bill Martin's Brown Bear, Brown Bear, What Do You See? to Nancy White Carlstrom's Jessie Bear, What Will You Wear? (Not surprisingly, rhyme and rhythm often go hand in hand, and often the same text uses repetition.)
Compression of statement is especially characteristic of picture books. If a picture book tells a story, it has the usual beginning, middle, and end, but the tale is told sparingly, with a minimum of text distilled to essentials, leaving the descriptive elements to the illustrator and evoking tone and tension in a minimal usage of words. This is especially true in Lana Button's Willow's Whispers, told sparingly, but capturing Willow's development from a shy whisperer to someone who can speak up for herself through her own invention of a "magic microphone".
Here's an adventure for the new year: Visit your neighborhood library and check out poetry collections and current picture books. I'd be interested in your own discoveries of picture books that illustrate one or another of Minot's four poetry characteristics. Let me know what you find out.