I would like to use in a new song a modified version of the refrain:
Oh, it is the biggest mix-up that you have ever seen.
My father, he was orange and me mother, she was green.
My refrain is not exactly the above, but close enough, so that many I'm sure will get the connection between it and the refrain of the Celtic song, "The Orange and the Green."
The rest of the lyrics will be entirely different.
Moreover, the melody will be the same as that of The Orange and the Green, which, unless my ears deceive me, is the melody of "The Rising of the Moon" which dates back to the 19th century; and so, there should not, I expect, be any copyright violation on my part by using it.
Now, back to the lyrics:
I have tried to find out when and where the modern lyrics (those which make use the above refrain) may have been copyrighted, but the most I have come up with is that "The song was written by Anthony Murphy of Liverpool"; see https://en.wikipedia.org/wiki/The_Orange_and_the_Green
I can't seem to find out anything else; e.g., when the song (lyrics, I presume) were composed, and where they were first published---U.K., Ireland, or perhaps, someplace else.
Duration of copyright is different in the U.K. from that of Ireland.
I am under the impression that in the U.K., 50 years from the year in which the sound recording was made is the duration of a song's copyright. It can last for 70 years if it were published and/or made available to the public.
In Ireland, generally speaking, the copyright expires 70 years after the death of the author.
So, without knowing when and where the above refrain first publicly appeared, or who Anthony Murphy of Liverpool is or was---
QUESTION: May I make use of a slightly modified version of the above refrain in a new song, using the underlying melody, The Rising of the Moon, in a song yet to be written and first performed (I expect) in the United States?
If the answer is No, then what may I do to find out who's permission I need in order to use a refrain slightly modified from the above?