Why does it really matter why they chose to sing it?
But that is an interesting question!
I was wondering, first of all, if there are different songs by that name. The only one I can find in a quick internet search is the reggae song released in 1970 by the Melodians (
hear it on YouTube). How odd, I thought, that this folksy song from Jamaica would be so well known and loved in Ireland in 1979 that they chose it to honor the Pope’s visit! Or could it be that they were singing an altogether different song by the same or similar name?
According to one source, Joe Duffy’s autobiography called Just Joe, Father Michael Cleary, one of the local organizers of the event, “kept urging us to sing ‘By the Rivers of Babylon’, saying ‘Boys and girls, make sure the Holy Father can hear you. Ah come on, you can do better than that!’” So it would seem that the song was deliberately chosen.
A quick search of the internet and YouTube turned up a few videos of Pope John Paul II’s visit to Ireland, but I found none that had a song about the Rivers of Babylon. A couple of videos did have other songs that sounded like the usual sort of hymns. So I don’t know whether this was the version of “Rivers of Babylon” that was sung. If it was, I would be curious about the local Irish culture at the time which influenced this selection.