One of my favorite Celtic Christmas songs was made famous by Bing Crosby. It's a delightful song with a toe-tapping melody. I had Samantha Gillogly give it an even more Irish sound with some fantastic fiddling.
You can get this and other Celtic Christmas music as part of my Celtic Christmas Greeting Cards that are now on Kickstarter. Go to http://celticmusic.org/CelticChristmasGreetingCards