Words are made of syllables, and some syllables are louder than others. We call the loud syllables stressed and the soft syllables unstressed. Consider the word 'destroy.' The second syllable is louder than the first, so you could say that the word follows a pattern of unstressed, stressed. Poets have names for these patterns. A pair of syllables that follow the pattern unstressed, stressed is called an iamb. Figuring out patterns in poetry is called scansion. Skilled poets have a finely tuned ear to the sounds of syllables, and by stacking together stressed and unstressed syllables, they can create rhythmic patterns. If the lines of the poem follow a regular pattern, that's called poetic meter. Traditional poetry usually employs meter, and this quickly sets a poem apart from regular speech. Meter can also establish the mood or tone of a poem. Depending on the type of meter that's being used, a poem can be formal or playful, romantic or aggressive. Think of how drummers can set the mood for a song by varying their speed and volume. Poets do the same thing with meter.
