It has indeed appeared in many books formal and informal, and has apparently become a staple of the community choir circuit both sides of the Atlantic. But nobody seems to have found out just where it came from, what language it is in, and what it means.
Possibly an instruction to a man to put his banana in a lady's hat, according to one theory. That puts it, if true, in a very familar class of folksongs: the vegetable double-entendre.
    But I'm sure there's a story here, who was the first person who learnt it in Africa, and brought it back to their choir. And did they in fact remember it correctly?
Joe Offer:
It starts
Si si si si dolada(phonetically). That accesses a tantalsiing amount of theories via google, but not enough hard facts.