Poetry is the earliest form of literature. It existed long before fiction, though early poems, such as the Iliad, often contain stories. Most likely, refrain and sound devices such as rhyme helped people to remember, recite and pass on history and lore. A variety of poetic devices contribute to sound in a poem.
Most people are familiar with end-rhyme, a device of lullabies and nursery rhymes, as well as of sonnets and other formal verse. You probably grew up with it. Some end rhyme is obvious, such as "cat" and "hat." But poets use other more subtle end rhyme as well. Words such as "language" and "rage," for example, rhyme because they share the same sound at their ends. Additionally, slant rhyme utilizes two words that nearly rhyme, but not quite, as in Theodore Roethke's "My Papa's Waltz." Notice the clean end rhyme in lines one and three, and the slant rhyme in lines two and four:
The whiskey on your breath
Could make a small boy dizzy;
But I hung on like death:
Such waltzing was not easy.
Other Rhyme Types
Alliteration, or repeated consonant sounds, is one other type of rhyme. Sibilance is a special kind of alliteration, referring to repeated "S" sounds. Consonance refers to a repeated initial consonant, as in "Better buy Buick." Assonance, or repeated vowel sounds, represents yet another type of rhyme. While alliteration often contributes to emphasis and rhythm, assonance helps to create a softer musicality. You will nearly always find it scattered through a well-crafted poem, creating subtle rhyme. In Li-young Lee's poem "Furious Versions," note the example of alliteration in the repeated "Z" sound in these lines:
These days I waken in the used light of someone's spent life, to discover the birds have stripped my various names of meaning entire: the sparrow by quarrel, the dove by grievance.
You can hear it twice in "these days," and then again in "used." In the last line, notice the repeated "V" sounds. You will find consonance in "light" and "life," as well as assonance. Sibilance repeats itself in "someone's spent," "birds," "stripped," "various names" and "sparrow."
When poets use words that sound like what they represent, they are using onomatopoeia, pronounced ahn-oh-maht-oh-pee-uh. "Buzz," for example, sounds like a buzzer. "Boom" gets your attention in a sudden way, the same way the boom of thunder does, echoing the same low, loud noise. In Langston Hughes' "The Weary Blues," he uses onomatopoeia in the first line of this couplet:
Thump, thump, thump, went his foot on the floor. He played a few chords then he sang some more--
Rhythm and Meter
Rhythm concerns the syllabic count and emphasis in poetry. Each line is made up of words, and the words are comprised of syllables. Each pair of syllables is a foot. In each foot, various combinations of stressed and unstressed syllables lend the line its rhythm, or music. Each pairing combination has a name. If the first syllable is unstressed and the second one stressed, the pair is an iamb. Two stressed syllables in a row make a spondee. There are four other combinations. Meter refers to the length of each line as it is counted in feet. A line of 10 syllables, or five feet, is written in pentameter. Trimeter refers to lines of six syllables or three feet. Each formal line length has a name based on its number of feet. Poets manipulate rhythm and meter to create a pleasant musicality. Formal poets use a form, such as a sonnet, to craft a poem by adhering to the form's prescribed number of lines, number of stanzas, line length and sound pattern. Sonnets, for example, always contain 14 lines written in iambic pentameter. They may have one or two stanzas. There are many formal sound patterns, and sometimes, poets make their own forms, as in Roethke's "My Papa's Waltz." He uses end rhyme and breaks the poem into four regular stanzas with a regular meter of six syllables, seven syllables, and six syllables, seven syllables repeated.
Sound in Free Verse
Though many people believe that free-verse poets do not take sound into consideration, the opposite is true. Free verse does not imply that the writer can put anything on paper and call it a poem. Attention to imagery, metaphor and sound is equally important. Free verse poets make liberal use of assonance, alliteration and consonance. They also work to shape the lines so that they work well rhythmically, sometimes emulating speech. LI-young Lee's "Furious Versions" is an example of a free-verse poem.