I don’t know how common a carol like “Silent Night” is sung on the Ould Sod, but there’s a website that has the lyrics translated into some 300 languages–including Latin, Esperanto, and Klingon! 
Anyway, here are the Irish lyrics I copied, without the diacritical marks (this computer doesn’t support them):
Oiche chiuin, oiche Mhic De,
Cach 'na suan dis araon,
Dis is dilse 'fair le speis
Naoin beag gnaoigheal ceannanntais caomh
Criost 'na chodhladh goseimh,
Criost 'na chodhladh goseimh.
What I would like to know is how to pronounce these lyrics if I want to sing them, given the considerable difference between spoken and written Irish. Thanks very much. 
Just asked my Irish-as-a-first language (gaelgoir) wife, and she gives you the following (my transliteration, as I don’t know phonetics properly):
EE[ch]u [ch]oo-EEN, EE[ch]u mi[ch] deh,
Cau[ch] na sooEEN dish arEHN,
Deesh iss DEELshu FAI-duh le spaysh
Neen beug NEH-oy-al KYAN-un-tash cweev
C[lr]eest nu [ch]OLuh gu-SHAVE,
C[lr]eest nu [ch]OLuh gu-SHAVE.
Where [ch] is a soft sound at the back of the tongue, similar to the ‘gh’ at the end of Scots “lough”, and [lr] is a cross between an ‘l’ and an ‘r’, like the French ‘r’.
Bear in mind that different Irish language accents make significant differences to pronunciation, and hers is specifically Connemara.
Also, the lack of diacritical (fada) marks might have caused her to mispronounce certain words, because she’s a better speaker than a speller. I can’t believe your computer doesn’t “support” them; just that you don’t know how to enter them ;). There’s a helper here from which you can copy-and-paste.
Thanks for the info.
My computer at home supports them. This computer is at a public library.
Here are the lyrics I used in the OP, with the “accented” vowels in boldface:
Oiche chiuin, oiche Mhic De,
Cach 'na suan dis araon,
Dis is dilse 'fair le speis
Naoin beag gnaoigheal ceannanntais caomh
Criost 'na chodhladh goseimh,
Criost 'na chodhladh goseimh.
I hope this helps.
Didn’t Enya record this once? She does ‘haunting melodic lyrics’ better than almost anyone.
Now THAT sounds interesting!
Golly, does all singing in Irish sound that way?
I still don’t understand why you can’t copy and paste. Or is it a 486 with Windows 3.1 or summat?
BTW you should check out Sinéad O’Connor’s version of Silent Night. It’s sung in English, but I’ve never heard anything else that sends the hairs on the back of my neck so amazingly skywards. And I don’t really even like her or her stuff normally. But… wow.
yes, enya did record silent night in irish. it is on a stand alone cd.
Not sure what a stand alone c.d. is, but the enya “The Christmas EP” c.d. I have has (count 'em) 5 songs: “Oiche Chiun” (Silent Night), “As Baile”, “'s Fagaim Mo Bhaile”, “Ebudae”, and “The Celts.”
Here’s my best shot at a phonetic pronunciation for the first few lines of “Silent Night.”
“Hee hee ma hule, Hee ha vay che”
Calma sul chee shaday
Chee shez stree che far day nay spays"
Obviously, Celtic isn’t my first language.
I have no idea other than that it’s a more modern Windows version. I’d have to ask a technician at the library–City of Torrance–to find out.
Sure, I can copy and paste on the library computers. Would I use that link that you showed?
the cd i have of enya singing silent night, just has silent night and an instrumental.
You were robbed. (Though there’s nothing really Christmasy about any of the other 4 tunes and I know that, at the very least, the second song had already appeared on another c.d.