"If you paid £30 or £40 pound to see a football match would you be just as happy if 13 or 15 lads came out with an oval ball?"

"If I bought a tin labeled 'salmon' and go home to find it was full of butterbeans because John Wests had decided salmon wasn't making enough profit, I would be entitled to go back and complain and, if doing so had caused me time and expense, some recompense (after all, the word "salmon" isn't copyrighted
If they persisted, I would be entitled to sue them.

'I think I know what folk/traditional song is - have spent over half a century trying to come to terms with it."

There is damn little traditional "calypso" on history's first and only million seller calypso album (Calypso, Belafonte, RCA LPM-1248, 1957.) And there were hundreds of other artists and songs from around the globe that self-defined as "calypso." Yet I don't know a single university professor of West Indian music who doesn't insist on hewing to a rigid, dictionary definition of calypso as Trinidadian folk.

In the half-century of my own research I've found academic, textbook and/or Mudcat definitions are about as relevant as pocket lint to the overwhelming majority of music makers and consumers (and fwiw, the true history of caribbean pop/folk music.) No refund, no return.