This covers a wide range of music as the list above indicates.
One decent compilation that covers everything from traditional jigs and reels to contemporary songwriting and the link to American artists is Bringing It All Back Home from 1991-I'm not sure it is in still in print.
http://www.allmusic.com/cg/amg.dll?p=amg&uid=UIDMISS70401081748502113&sql=Ajcv1z87a3yv1
One decent compilation that covers everything from traditional jigs and reels to contemporary songwriting and the link to American artists is Bringing It All Back Home from 1991-I'm not sure it is in still in print.
http://www.allmusic.com/cg/amg.dll?p=amg&uid=UIDMISS70401081748502113&sql=Ajcv1z87a3yv1