BBC Tess of the D'Urbervilles song

[VideoJames]

What is the name of the song that is sung by Tess throughout the presentation [for example, the song that's sung in the scene with Tess and her friends as they were made to work all night in the barn]... you know which song I mean, right?
It's really beautiful and I just wanted to know what to call it...

[VideoJames]

never mind - I've found it. It's called "The Snows they Melt the Soonest" or "Kr�sn� l�to" in an unfamiliar language... [i think maybe it's Gaelic? I'm unsure though....
Beautiful song.