BAZ can you read Welsh? There's a ballad of the 1st half of the 1630's in 'The Pepys Ballads', P, p. 457, 1987, that's in Welsh, "Byd Y bigail. Being the same in Welch, to a daintie new tune." At the end is 'Terfyn R. H.' I have no idea what the ballad is about.
In my broadside index is listed a song of the 'Clarke of Bodnam (Bodmin)'. It's no later than 1624.
Since the last update of the index I've found out what old tale Sedany/ Welshe Sydanen got her name from. She was the 'Lady of Sinadone' in North Wales, rescued from an enchantment then married to her rescuer.
Anyone have the version of the tune "Sedany", called the "Melody of Cynwyd", from Edw. Jones' work on the Welsh bards?