Here are some excerpts from the “Creative Screenwriting For Dummies” series.
A well-crafted verbal exchange is like a catchy song. Diction provides the lyrics; music provides the tune. Dialogue relies on the sounds of words as well as their definitions, on the rhythm of a conversation as well as its meaning. If you block the literal significance of a discussion and isolate the sounds that it’s made up of, you discover a rhythm holding the entire exchange together.
Shakespeare wrote in the unstressed-stressed pattern of iambic pentameter. Why? Because it mimics the cadence of natural speech. It’s lilting. The dialogue of David Mamet and Oliver Stone explodes off the page. Why? They use explosive words in an explosive way. The result is verbal fireworks.
The music component of dialogue is responsible for any mounting tension or emotional undercurrent in a scene. After you know what types of phrases your character utters, rework them with an ear toward melody and percussion. Which voices enhance each other? Which are combative? What is the character’s state of mind at the time he speaks? How can you convey that state of mind through sound alone? Joy, fear, anger, grief, awe — these emotions have unmistakable rhythms; listen for them around you, examine their form, and then try to recreate them on the page. Like a catchy song, eventually, they’ll stick with you.
The terms ALLITERATION and ASSONANCE are often used in poetry, where an ill-chosen sound can make or break the piece.
Alliteration refers to the repetition of consonants and the effect of that repetition on the listener’s ear. Imagine a tiny percussionist sitting inside each word, matching an instrument to each consonant and sounding them in succession. Perhaps he pounds the hard “d’s” out on a kettledrum and taps the “t’s” out on a snare. Maybe he selects wood blocks to create the “ch” sounds and shakes a rain stick for an “sh.” In any case, he repeats the sounds of each word in such a way that they produce an audible rhythm. That rhythm is alliteration.
Alliteration is helpful when you want to punch a line or emphasize it for your audience. It also tends to speed a line up.
If it’s punctuation or percussion that you’re after, alliteration’s your approach. If you’re trying to produce a specific tone, it’s assonance you’re after.
Assonance is the repetition of a vowel sound within a phrase. Assonance creates the pitch or timbre of a conversation.
When repeated in direct succession, vowels can mimic the human voice. A sentence full of vowels may produce a subtle moan, wail, squeal, or cry. In this way, assonance helps to create an emotional soundscape for a phrase, a speech, and possibly an entire conversation.
If alliteration speeds a sentence up, assonance slows it down. If alliteration provides a backbeat for the conversation, assonance heightens the mood. Together, they help a writer generate a distinct palette and rhythm for a character’s voice.