In Ireland (and England) 9/8 is usually 3 dotted quarters, or 3 x quarter+eighth, not 3 quarters and a dotted one (i.e. only three beats in the bar, not 4)

Plenty of slip-jigs (Rocky Road to Dublin, The Foxhunt) or country dances (Sir Roger de Coverley). I've heard tell that tunes in this triple rhytm tend to be much older than a lot of 4/4, 2/4 or 6/8 tunes, but I can't prove it.