This is a real blast from the past, but I have only just discovered Ryan Davies. This one is rather charming especially for those of us of a certain age:
Rhywle Draw Dros yr Enfys
Someone has posted the lyrics, although I don't think they are 100% correct (as in, don't quite reflect what was sung).
Edit: I've now had chance to read a little more about him and sample some more of his work.
Such a great talent - such a great loss.