Some more Celtic choices
It's kinda amusing reading the lists on this thread. I'm about as Irish as Paddy's pig (very – just in case you've never heard the expression). I've never heard of most of the groups here. Not that it matters. Perception is as important as fact in choosing the music. Since it is most likely the music will be played for a varied audience, what they believe is Celtic (hard C, K sound by the way, not a soft C like the basketball team) is as important as what is really Celtic. For example, Danny Boy, what many Irish-Americans consider an Irish staple wasn't written by an Irishman nor even in Ireland. The lyrics were written by an Englishman. The tune's origins are a bit more foggy. Most recent immigrants from Ireland never heard the song before landing here.
Although I believe HoustonDJ is referring to Celtic influence appropriate for any time of year. I'd like to ask what do you play for St. Patrick's day? Even for a pack of Mics we'd play 60 but no more than 90 minutes of traditional music then the regular fare – what ever will get 'em dancing.
To me, Irish comes down to two major genres, jigs and reels or the ballads. One heck of a lot of my Irish friends couldn't take many jigs and reels before they went postal. Allow me to say I wasn't too far behind them. God bless HoustonDJ's Celtic heart but most [modern Irish] wouldn't know how to dance to one so playing one while people are dancing might be as popular as a you know what in a punchbowl. The remainder of the genre is the ballad typified by Tommy Makem. Tommy Makem died last year. A familiar baritone voice he's best known for singing with the Clancy Brothers. One of his best known “Four Green Fields” is thought to be, even by the Irish to be a traditional composition. I could go on but you get the idea. In any case, much of the music has to do with the Irish diaspora. Millions were forced to leave Ireland or starve. Many more did stay and perished. This was a direct result of British policy. Had this happened more recently Britain would have been held in the same low regard as South Africa was before the resolution of their troubles.
Here's some traditional groups that are synonymous with Ireland that no one mentioned
Tommy Makem
Clancy Brothers
Irish Rovers
Chieftains
Dubliners oops, someone mentioned them?
More recent sound:
Colcannon
Altan
Mary Black
Clannad - Enya sang with them for a time in the '80's
One track that I'd like to share with everyone is Altan's “Dulaman”. It's sung in Gaelic but has a throughly contemporary sound. The Celtic Woman also sing Dulaman but the Altan version is superior.