OK
Here is the end of the song, i.e. the bit in the iplayer, as I hear it, about one minute long
It is in that posh opera type voice when they sound like they are trying to enunciate but actually it is somewhat indecipherable. So I'm only confident(95%) in the bold text.


foie gras, ha, ha.
In the back streets of hell
sat the brath Brasserie
Belshazzar,
Belshazzar
where my lord and his guests
at all hours you may see
by the bar
Yes there they are
stretched out on hot toast racks
basted with grease
while ganders make snacks
of their livers obese
and the mother geese gobbled
and moreyed in grease
Ha Ha Ha [this sounds like French] fo mavoir
(inaudible) encore(inaudible)
[English]So it's 'bon appétit'
and service for free
at the bar
Ha! Ha! Ha!
Foie gras!!!

Sung by the baritone Richard Jackson
Pianist Graham Johnson