I said
"Another instance of variability is in Cecilia Costello's alternative cadences for The Grey Cock, implying major or minor"

Jack said
"They imply no such thing. The modality of a tune is not determined by the pitch it ends on."

Perhaps I should have said "suggest" rather than "imply". The note that a tune ends on is a very strong indication of the tonic. The same notes with different tonics strongly suggest different modes/scales.

But perhaps a better comment on Cecilia Costello's alternative versions is that it illustrates the variability.