We have put a sound file of this song on our site http://www.treewind.co.uk/mha/mha-recordings.html
It may be this one which you heard.
I have put a couple of floating verses from the Welsh tradition into the middle of the song because it is so beautiful and so short! I wanted to spin it out a little longer.
The verses are very like the one Sian has typed in. The meaning is the same - the dialect, reflecting my origins, is more North Welsh, ( even though the song was collected in Barry, South Wales.)There is a story behind the song. It was collected by a teacher ( as I am at work, I forget his name ) from an old lady in Barry. She wouldn't let him go away until he had learnt the song orally. He kept having to sing it back to her until he was note and word perfect.
I suppose two verses isn't too hard to learn in an afternoon.
Hope you all go away and learn them!