I don't believe there is a correct or incorrect formula, but definitely some interesting arguements here. Many artists have tinkered ... Stevie Wonder has some songs that are Chorus only, for example (I belive the song "Isn't She Lovely" is one such song).

I have a tune (below) that has the chorus built into the verse (the music does not change, only lyrics). This creates an AAABA feel, even though it has a true Chorus. I also like to slightly alter key lyrics in my choruses so that they don't exactly repeat. In this song, the words "go, go, go" become "run, run, run," etc. Check it out: free audio on iLike

Kentucky Sun
I can't live in the city anymore; too many women in the night.
I'm headed for the Bluegrass State where people love the light and I will run.
I'm on the run, run, run.
Yeah, I gotta get to the Southland so I can see Kentucky sun.

They call it "the meadow land," the "land of tomorrow."
From the Cumberland waterfall, to the sassafras of Owensboro.
I got to go, go, go.
I'll find peace in the Southland underneath Kentucky sun.

The riverbank near Louisville is "dark and bloody ground."
Lush hills of goldenrods. And then there's the state fair grounds.
There's enough for everyone.
So get to the derby and help yourself to Kentucky sun.

I'm not from the Big Apple with its neon night.
I come from the Bluegrass State - I got to spread my wings and fly.
And I'm on the run, run, run.
So get to the Southland and help yourself to Kentucky sun.

© Nick Edelstein (BMI)

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