Following on from the contributions by Brían and others to the thread Breastplate of St Patrick, I've been listening to a wonderful CD of Gaelic Psalm singing (Gaelic Psalms from the Isle of Lewis from tapes in the archives of the School of Scottish Studies, issued on the Greentrax label CDTRAX9006.
I was intrigued by the sleeve notes which claimed that early Psalters used ballad metre which would be familiar to the congregation (but not to the Gaelic speaking populace for whom the Psalms were translated,using the Lowland metres which were foreign to their tradition,but which they retained when church music was reformed in later centuries).
Does anyone have any sources of information on ballad airs used in early (17th century)psalters? there have been previous thread discussions on traditional/folk tunes used in hymn tunesHymns and Folk Tunes and Songs of Faith
I have another interest: I've come across a reference to an MS in the British Library which contains an Irish translation of The Song of Songs from 1709 which has an interlineal refrain:

Callíon ó shruch Íordáin mé.
which is phonetically similar to the "lost"song Cailín ó Chois tSiúre mé
Is there a lost Irish tradition of psalm/biblical singing?