Well, according to Peter Kennedy, both the tune and the words were first noted from the singing of Cornish lead miners in Germany (I'm not making this up!). They, and various other Cornish and Devon sources, said it had been sung there for generations at pay-days and wakes. Baring Gould later noted the tune from someone in St Ives, but also heard it sung in various other parts of Cornwall. So although it may not have been referred to as the "Cornish Nightingale" until much later, it was certainly identified by the mid 19th century as a long-established song in Cornwall and Devon.

Marje