Assonance, or the art of matching vowel sounds in lines of text, is used in poetry mainly to produce specific sound combinations that trigger literary or auditory associations in listeners and readers. Assonance can be used to make a poem sound different, and also to provide “clues” for literary symbolism. Along with assonance, writers also use different kinds of consonant patterns in poetry, including alliteration, or agreeing consonants at the beginnings of words.
One main use of assonance in poems is to help the text “flow,” mainly from an auditory perspective. Choosing agreeing vowel sounds gives a line of poetry a sort of streamlined sound that can be more accessible to readers with a “musical ear,” or others who appreciate phonetic tone in poetry. Flow is an element of modern types of poetry, for example, in stream-of-consciousness or “beat” poetry, styles influenced by a more modern way of thinking about verse.
Another way to use assonance in poems is to use agreeing vowel sounds in important words, generally in nouns, to trigger an association between two ideas. For example, if a writer combines two assonant words like “corn” and “morning,” it can help to create a sort of subtle link between the two things. This idea works with proper nouns as well.
Some writers may also use assonance in poems to create “bright sounding” lines or other distinctly toned lines. A line like “apple blossoms wrapped in satin” has a sort of bright tone when spoken aloud, relying on the “bright” short “a” sound. This is another way that this literary convention can come in handy in constructing poetry that sounds as good as it looks on the page.
Assonance is particularly effective for poems that are written for “readings” or to be performed. In contrast to traditional forms of poetry that are primarily read, performance type poetry needs to be written with an ear for its verbal form. Where consonant methods like alliteration tend to have more diverse sets of uses in poetry, assonance in poems mainly relates to the idea of “visually expressed” meter.