When living in Ireland I noticed how Irish Folk songs would often recount hardships experienced in pre-independent Ireland, or even directly criticize British rule. A well-known example is 'Fields of Athenry' (lyrics) with its comment on the Irish Famine and lines like "Against the famine and the crown, I rebelled, they ran me down".
This led med to wonder if music or literature were used not only to criticize, but also as a means of initiating or organizing resistance, possibly through writings in Gaelic. I suppose the time-frame would be the late 19th to early 20th centuries.
The 2nd question goes a bit further back in time. It relates to the Celtic Revival, and to the transmission and possible modification of Celtic folklore/traditions through later cultural works in Ireland, as well as their relation to Republicanism.
Any input or reading recommendations would be highly appreciated.
Could I just point out that your example wasn't written until 1970, so could not be an example of Irish folk songs being used to provoke resistance. Most popular Irish folk songs, often described as "rebel songs" post-date independence, often by decades. "Dublin in the Green", about the Easter Rising, for example was written by Dominic Behan, supposedly when he was 12 years old, which would make the year 1940.