Malcolm Douglas is right,every country has many different styles,including IRELAND,
Bess Cronin,Sarah Makem,MargaretBaRRy,PaddyTunney,JoeHeaney.are examples
there are a number of revival performers who sound as if they have listened to traditional singers, Roy Harris,Lou Killen,Harry Boardman,Ian Woods Nic Jones[early recordings] ,Kevin Mitchell,Sean Cannon,Ron Taylor Anne Briggs,IsobelSutherland,BrianPeters,FredJordan PeterBellamy.
as traditional singers were frequently unaccompanied,the use of ornamentation in the voice is fairly important.
When a SINGER accompanies himself he has the added option of chordal harmony,and consequently doesnt have to use as much interpretation,
there are of course exceptions Peter Bellamy[highly ornamented whilst accompanied].Bob lewis GeoffWesley[unaccompanied small amount of ornamentation]