Skipper Jack, I just looked at your message again in which you said
"Nos Galan, Glanbargoed, Llwytcoed" That suggests to me that the tune is "Nos Galan" and that it was collected at Glanbargoed, "
Sorry - a bit more on that ... I'm pretty sure that Nos Galan, Glanbargoed and Llwytcoed are three separate tunes that are played in a series (with a return to Nos Galan at the end) thus serving as a full set for Dawns Blodau Nantgarw. I know that, in Blodau'r Grug, Nos Galan is one of three - I can't just remember if G & Ll. are the other two.
Liland, in Welsh texts we do use Ffa (which only co-incidentally means 'beans') but who's gonna quibble when God gave us 'cut-and-paste'? But I'm VERY impressed that you understand Cymro/Cymraeg/Cymreig ! There's many as don't! The local supermarket advertises Welsh speaking cheese ...