It occurs to me I may sound like a broken record (78 rpm of course) in saying over and over, "floating verses, floating verses."

But really, they do get around, it's one of the commonest characteristics of southern lyric songs. Take:

Liza [Cindy, et al] in the summertime, Liza in the fall,
If I can't have Liza all the time, don't want Liza at all.

Occurs in Liza Jane, Cindy, and a dozen other songs. Another:

She threw her arms around me, said she loved me some,
Threw her arms around me, I thought my time had come [OR: like a grapevine round a gum]

Then there's the verse

Yonder comes my [your girlfriend's name here], how do you think I know?
Know her by her apron strings hangin' down so low,

in many, many songs, both African-American and white. As are the "raccoon and possum" verses, and so on and on.

Such a huge assortment of verses appropriate to throw into whatever song you happen to be singing has made it difficult to clearly separate some songs from others. Banjo pickers tend to center such verses around a refrain with a strong image, like Old Joe Clark, and sing indefinitely. In fact before 78 rpm records made the standard length of a song approximately three minutes, it was common enough to string songs out by means of floating verses to lengths of five to ten minutes or until everybody'd plainly had enough.