Tom Lehrer's "Be Prepared" about boy scouts would qualify.

The best I ever saw at the Eistedfodd at Southern Massachusetts University
was the Dirty Songs Workshop with Cliff Haslem, Peter Marston, David Jones and I think Louis Killen was there.

They did fifteen minutes on The Ball of Ballymuire, each verse raunchier than the other.
When the workshop was done, I gazed out into a sea of red faces and laughter.

I'm not comfortable about repeating these verses here. But if they ever do a Dirty Songs
Workshop again, don't miss it.

Frank