In the previous poem it seems to me that Lewis Glyn Cothi alludes to the area within the Builth hundred that harboured outlaws - Drum Ddu. We know that Lewis was an outlaw himself at one period, so he may have know the area from then - the outlaw bard Llywelyn ap y Moel almost certainly did. Drum Ddu continued as a rebel stronghold well into the sixteenth century and even later - no doubt it was more heavily wooded then than it is today.
Anyway, this enables me to make a tenuous link to the fretless bass player Percy Jones, who included a track entitled Drum Ddu on the Brand X album Manifest Destiny. Now jazz fusion is not my scene but you can check out Radnorshire born Percy's interesting website here. One thing mentioned on the site is a CD of R&B tracks made from an old tape recording of The Viceroys playing at Glasbury Village Hall in 1965. In a way that CD must be almost as fragile and rare a piece of historical evidence as some of the manuscripts containing the old bardic poetry.