Dear Yankees and fellow travelers; Down south you would be considered priggish if you exclaimed "Oh Crackey!" The southern and correct expression is "By Crackey!".

milum has this right. There was a novelty song popular in the 1930's called "I Love Mountain Music":
I love mountain music,
Good old mountain music,
Played by a real hillbilly band.
When I hear that rhythm
Let me sway right with'em.
I think the melody is grand.
I've heard Hawaiians play to the tune of the wicky-wacky,
But I must say, I'd rather hear Turkey in the Straw, by Crackey...

Don't know who wrote it, but I'm fairly sure it wasn't Cole Porter.