No lyrics, I'm afraid, but a web trawl gives a little information: St Keverne was from Cornwall and lived around the sixth century A.D. There is a village named after him, and a band, also a flower. There is a hymn tune called "St Keverne". His feast day is 18th November. This is probably not what you wanted, Lucy, but at least it brings the thread to the top of the Forum again.

Joan