Structure is vitally important in any piece of writing. Structure is the road your readers walk on to get them where you want them to go and the signposts indicating what you want them to notice; without it, they're lost. This is true in persuasive writing, in non-fiction, in fiction, in prose, in poetry, and in song.
The ballad is a key structure in the English language songwriting tradition. Though the word has been misappropriated by today's pop songsters, it originally meant not a slow song about love but 1) a narrative song 2) structured in a series of identical verses (i.e., not having a chorus, bridge or other lyrical part structured differently from a verse).
I have written many pseudo-ballads and near-ballads and a few true ballads. The following is one of my true, nail-on-the-head ballads. It's called "The Captain", and it started as an experiment in rhyme scheme inspired by Leonard Cohen's "Suzanne".
Oh Sally, she married a soldier
A captain named William Lee
I guess in his fashion he loved her
But Sally always loved me
Now I sit by this stone and remember
Her blue eyes and tresses of gold
And how we said when we were younger
We'd be together when we grew old
The captain was usually sober
At night he was usually home
On bad days he yelled and he beat her
Breaking her pride with her bones
You know I was never her lover
But not because I never tried
She just lay every week on my shoulder
And whispered my name as she cried
One day he found us together
Just talking, but we were alone
Pulling his pistol he pushed her
And shouted all the way home
Next morning, I came to her front door
She lay stretched out on the ground
In their Sunday best, everyone mourned her
But the captain, who never was found
Some say he left by the river
Some say he left by the sea
I guess it doesn't much matter
Since the captain took Sally from me
(Yes, I recycled the name William Lee for use in Witchy Eye. The characters are unrelated.)
Here's "Suzanne", for the fans. It isn't a ballad.
But "Lily, Rosemary and the Jack of Hearts" is.
And "By the Time I Get to Phoenix" is doggone close.