'The Death of Parker' was widely published on broadsides, and was certainly never illegal anywhere. It's possible that singing it in the Navy may have been a disciplinary offence at some point, but as I tried to explain earlier, that's a completely different matter and would have depended on the local context.

Nobody so far has come up with an example of a song proscribed by law anywhere (except for the particular case of Nazi songs in Germany), far less in Ireland; where, I suspect, our original questioner was probably thinking vaguely of songs 'made illegal' by the Wicked English before the establishment of the Republic.

Does anybody know of any identified examples (titles, please) and what the statutes concerned (if they existed) were?