Dick,
Whilst I agree in principle with what you say here, I will try to defend what Bob was saying. First of all he was obviously alluding to Britain specifically. Secondly he uses the word 'possibly'.

If I can be allowed to add my interpretation to what he said...rugby songs are close to a pure living oral tradition within a particular and well-defined community. Of course he was wrong to suggest this is the last example, children's playground songs and lore are equally (but not totally) pure. Dick also added 'soccer songs' by which I presume he means 'terrace chants' and of course he is absolutely correct on that score.