Rheged

Rheged is not in fact in Wales, but I've placed its centre in Cumbria, where there is now a heritage centre of the same name. It was one of the kingdoms of the Hen Ogledd (Old North). It was a Brittonic-speaking region with its own dialect, in what is now Northern England and Southern Scotland, although its borders are nowhere clearly delineated. It appears in poetic, bardic and historic sources during the post-Roman era and Early Middle Ages.
This charming tune is a waltz in D, and I've added quite a lot of B minor into the harmony parts to give it a more sonorous sound.