Thanks for your reply and scrupulous clarification, Siân, I appreciate it.

I was (still am) genuinely curious to know what exactly "the sound" is that you're looking for, that we failed to capture, unless it's the use of mixed voices that you can't stomach. I for one would love nothing better than to sing in a "proper" male plygain group, but that's easier said than done when you don't live in the right part of the world. But women singing plygain is hardly that shocking, is it? Come to think of it both Arfon's Arbrawf Mawr workshop version of Carol y Swper and Parti Bronheulog's Hosannah Fawr are mixed:
http://www.youtube.com/watch?v=_8Anfd5QzMU
http://www.youtube.com/watch?v=1UyU8Z2FK_s
Then again, I don't have conniptions when I see female morris dancers, so perhaps I'm beyond help as far as the purists are concerned.

In fact, guess what? Just about everything we do is inauthentic, if by that you mean that we weren't brought up to it. We're not Georgian toastmasters or Bulgarian peasant women or sixth-generation Sacred Harp singers from Alabama, we're children of the industrialised twentieth century in the UK -- so sue us! Obviously we take it seriously, and listen and read as widely as possible, and reviewers have been kind enough to say it's clear we respect the music we sing, but we're not going to avoid singing something amazing that our many people have never heard and would love, just because we're not "tradition bearers". Songs are for singing, not putting in museums. As I'm sure you'd agree. And there should be more Welsh sung at folk festivals.

I too am puzzled by the scarcity of contemporary plygain recordings on YouTube or anywhere else on the web. But then plygain is perhaps not so much a specific musical genre as a Christmas tradition or activity. It's not often "performed" out of context, which I suppose helps explain why there are so few videos of traditional singers, at least. While we'd both have ideas on how it should be sung, the "sound" comes as much from the traditional harmonies as from the vocal timbre. Your tradition bearers don't put on a special plygain voice, different from the one they'd use to sing hymns at any other time of year.

For those unfamiliar with the sound of traditional plygain, here's Parti Fronheulog recorded in the 1960s: http://www.emusic.com/album/Amrywiol-Various-Caneuon-Plygain-Llofft-Stabal-Close-Harmony-Tr-MP3-Download/12211624.html
Also from the 60s, what do we think of the use of a big orchestral harp to accompany traditional plygain singers in this film?
http://www.bbc.co.uk/wales/christmas/sites/content/pages/archive-plygain.shtml
I can't help thinking that a purist would disapprove of that, and I can't say I'm wild about it myself.

I'm sorry I didn't remember meeting you at a workshop. We do a lot of workshops. At least, we have done, but if enough people start to believe casual unsubstantiated allegations to the effect that we don't know what we're doing, that could always change. ;-] (Tip: it's not true!) Reasoned constructive criticism, that's different: bring it on, say I, and back it up.

Also bring on better interpretations. Let's see a video of it done properly, that we can all admire. Till then, I don't think our version is too shabby, though of course I respect your right to dislike or disapprove of it, and I'm truly sorry it didn't hit the spot for you.

Pob bendith a phob dymuniad da, as my Nain used to say.
Harry