Tik-Tok visitors: Irish Catholic 'shantying' is c.1400 years old, not 600. Columbanus had Greek, Hebrew, Latin, Gaelic &c nouns and verbs for it. None of them would be shanty(ing.)
Not shanty: Heia Viri - Coro de la Universidad Carlos III de Madrid

Observer: I wasn't born at sea but… straight there from the maternity ward. My paternal grandfather was the last of the red hot telodynamic engineers (Google it.) Grampa Conchy would bust out a puirt à beul at the drop of a mallet or dip of an oar. Good times.
Also not shanty: Carolina Chocolate Drops LIVE "Mouth Music"

We understood the sort of thing on Tik-Tok today as the province of Kurt Hahn's Outward Bound culture. They were the nautical equivalent of play or campfire songs. The singers were overly prone to disaster at sea.

The only thing I took from the Gibb article(s) is the good professor still doesn't grok an instrumental or a Catholic African man… “Needs improvement.”