In 1962, E.G.R.Hooper published a collection of 80 hymns and 14 psalms in Unified Cornish under the title Lyver Hymnys ha Salmow. A second edition was produced in 1976, containing 91 hymns and 15 psalms. Most of the hymns were translated from English, and in my view, more effort was taken to obtain a close translation than to pay attention to the accent and scansion; as a result some of the hymns are practically unsingable.
I therefore began many years ago to translate hymns and carols into Cornish, and to ensure as far as possible that the accent and scansion fit the music properly. Two examples are given of how this may be done, translating from English and from Welsh.
Of the hymns taken from Lyver Hymnys ha Salmow, some have just been re-spelled, others have been tidied or partially re-translated. In some cases I have made a completely new translation. The spelling is that of Kernewek Kemmyn, as defined in Gerlyver Meur, but with two modifications: the use of z for the reflex of Old Cornish /-d/ in stressed monosyllables, and allowing for the different allophones of historic /o/.
The list of hymns in Cornish is found here.