As far as I can tell, very little recording of source singers took place in Wales. There was lots of transcription of tunes and airs, but little interest in the performance of songs by living singers. By the time relativly cheap portable recording became available and there was an interst in it much of the oral tradition seems to have died. There are still some traditions of course- Plygain in north Powys and parts of Pembrokeshire for example. It might also be worth remembering that much of Wales doesn't just have the one tradition. In the area where I am from there are people belonging to longstanding Irish, English, Chinese and Italian communites each with their own tradition, along with people who would identify themeselves with a Welsh or English language tradition. Add to this early industrialisation and a non-native middle class and its possible to see how a continuos tradition could be repeatedly fractured and not survive in an accessable form. Given that the early stages of industrialisation were peopled by arivals from rural Wales this would probably also weaken the rural traditon as well. For these reasons I think that the idea of a single unified tradition of Welsh folk music is problematical, and would rather think of the tradition as being one of individuals and communities continuously remaking and recreating 'tradition' as needed in response to changing social and economic conditions. Long live revival! So there! I would still like to know what's in the archives in St Fagans.