Here, an entire site devoted to bawdy and filthy songs:
http://immortalia.com/
Including the earliest known uncensored dirty songbook published in the US. Also includes a collection of mp3s that I haven't had enough time to download yet...
A selection from Immortalia:
The Sexual Life of the Camel
Oh, the sexual life of the camel
Is stranger than anyone thinks.
In moments of amorous passion,
He frequently buggers the Sphinx.
But the Sphinx's posterior passage
Is clogged with the sands of the Nile,
Which accounts for the hump on the camel,
And the Sphinx's inscrutable smile.