Most folk songs, on the other hand, follow an AAAA-AAAAA
pattern. "On Top of Old Smoky," for instance, repeats the melody and
pattern of the first verse for all subsequent verses. Consequently,
when the folk songs first began to appear in the mart of popular
melody, publishers required that "B's" be added to them.

In 1942, I learned at Fort Dix and ancient bawdy song which used in
its twentieth-century incarnation the refrain, "A Gob Is a Slob."
It derived much of its comic flavor from its AAAA form:

I walked down the street like a good girl should,
He followed me down the street like I knew he would,
CH: A gob is a slob wherever he may be
Listen and I'll tell you what a sailor did to me,
I walked to my house like a good girl should,
He followed me to my house like I knew he would,
CH: A gob is a slob wherever he may be
Listen and I'll tell you what a sailor did to me,
I opened the door like a good girl should,
He followed me through the door like I knew he would,
CH: A gob is a slob wherever he may be
Listen and I'll tell you what a sailor did to me,
I walked up the stairs . . . etc . . . etc . . . etc . . . etc.

As a result of the folk song revival, I was asked for some "folk songs
which might become popular." I offered the above retitled, "A Guy Is
a Guy." Mitch Miller, an important A. and R. man, agreed that the
centuries-old song had merit, but asked for a "B." And so, I
interrupted the "A's" with the following:

I never saw the boy before, so nothing could be sillier,
At closer range
His face was strange,
But his manner was familiar.

The song was recorded by popular singer Doris Day and was the number
one song of the year. I always wonder whether the "release" had
anything to do with the success of the old folk tune.

1962. The Ballad Mongers by Oscar Brand. pp. 99-100.


See here: https://archive.org/details/balladmongers0000unse_w9b6/page/99/mode/1up?q=%22gob+is+a+slob%22