At first: this is one of many singles Franco Trincale, a storyteller from Sicily, recorded thorough the years. He usually was around the Duomo (the cathedral) in Milan with his guitar in front of a panel with the drawings of the story he was singing about. He sang about politicians and everyday stories.
This record is about the divorce law approved through a referendum in the mid seventies. It was a hard fight and, obviously, the Vatican was against: this is why the priest in the background.
Terrone and polentone are depreciatory words used to define people from the south (terrone) and from the north (polentone) of Italy, even if today they are used mainly as a joke. Franco recorded about ten singles on these characters.
Maybe in this case they were used because in northern Italy people were for the divorce and in the south, much more conservative, against. A forcing, to be honest.
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Looks like one of that trashy novelty song from the sixties. terroni and polentoni are insulting terms to describe southern and northern italians. I don’t know who is who in the picture but it seems like that they want to divorce. at the time it was not yet possible, though.