I would question one line of the lyrics in the link PA provided (thank you for that link, by the way). Where it says:

SPENT THE GROCERIES AND HALF THE RENT
LIKE FOURTEEN DOLLARS AND TWENTY SEVEN CENT

I always heard:

Spent the groceries and half the rent
I lack fourteen dollars of having twenty-seven cents

(In other words, he's $13.73 in the hole, possibly a bar tab.)

And of course the last line should say "son of a gun", not "song of a gun".