A recently published volume "Rhythms of the Revolt: European Traditions and Memories of Social Conflict in Oral Culture", edited by ?va Guillorel, David Hopkin and William G. Pooley (Routledge, 2017) includes several chapters on folk songs.

In particular, a chapter by the Israeli historian Guy Beiner titled "The Enigma of 'Roddy McCorley Goes to Die': Forgetting and Remembering a Local Rebel Hero in Ulster" (pp. 327-57) is well worth a read.
It sheds new light on the history of the man behind the ballad and how he was repeatedly forgotten and remembered in folk memory.It clarifies how Ethna Carbery's ballad 'Roddy McCorley' became a popular staple of Irish folk singing, while older folk songs on Roddy McCorley became obscure.