An interesting case it put here by an academic for some of the "Traditional "   Irish ballads originating in England. I suppose the 1954 definiton of folk would cover this. However, it does show the folk process and there is every reason to suspect this continues today.
Around the Hills of Clare: Songs and a Recitation from the Jim Carroll and Pat Mackenzie Collection.
The songs are a mix of the very local, notably the bucolic title-track, 'Around the Hills of Clare', the grand pan-Irish, and a smattering of the general inheritance of balladry and narrative song in the English language. The latter suggests that broadsheet ballads, sometimes originating in England, were disseminated far and wide. In some cases, they doubtless found their way to the south-west of Ireland and were passed on from generation to generation long enough for them to mutate seamlessly into the local accent, to become part of the local tradition. Tom Lenihan's beautiful rendition of 'The Constant Farmer's Son' is an example of this, as is 'The Old Armchair' ('Fair Margaret and Sweet William').
(http://www.thefreelibrary.com/Around+the+Hills+of+Clare%3A+Songs+and+a+Recitation+from+the+Jim...-a0156004573)
DESI WILKINSON University of Newcastle

Dr Desi Wilkinson, has research interests in Celtic and Breton folk musics.