Don't use 'ceilidh.' Few people know how to pronounce it, and even fewer can spell it.

A few years ago, our club brought in a band from abroad that had 'ceilidh' in its name. Radio announcers butchered the word, and I'm sure there were stations that rejected our press release because they would look stupid trying to say it.

I wouldn't use 'barn dance,' either. Barns smell. For me, at least, the words 'barn dance' evoke cheap instruments which are not really in tune.

How do you like the phrase 'country dance'?

But if you are willing to play for parties where there is no dancing, then you don't want to take a name which says that you are purely a dance band.

Why don't you check a thesaurus for words and phrases which express 'everyone have a good time and never mind if in doubt, cheat'
'Nonchalant' comes to mind.