I'm sorry Greg, I'm not really a great musical scholar - its phenomena you can see, in the best Irish music pubs. hard to describe for a schmuck like me. I've not had a formal music training, and I'm English, and its not a style I have insight into from playing myself - a treble disadvantage.

the best celtic style guitarists I have seen, play in DADGAD. the chord changes are fast and complex - sometimes shadowing, sometimes anticipating the 6/8 of the bodhran. the plectrum sometimes sort of swoops and cops into vigorous rhythms, other times it plays the grace note riffs.

Not i might add in an ordered way like Lester Flatt or Mike Seeger, its more like a vigorous attempt to rip into the tune.

does that make sense. I suspect not. Start a thread about it and some Irish people will explain it better than I could!