Danville Curl: Meaning & Origin of the Folk Song Phrase

Question
The phrase "danville curl" occurs in several folk songs.  It refers apparently to a hair style.  If so, what does it look like?  Thanks

Answer
If you're talking about the Woody Guthrie song, Danville is a city in CA and Danville Curl is just a catchy phrase. He's talking about a girl from Danville and describing her.

If there is a particular style called Danville Curl, I've never heard of it and I spend a fair amount of time in CA.

Here's the lyrics:
I rode her down to Danville town, got stuck on a Danville girl,
Bet your life she was a pearl, she wore that Danville curl.

She wore her hat on the back of her head like high tone people all do,
Very next train come down that track, I bid that gal adieu.

It's not a specific style. Just a phrase with enough syllables to work. :c)