Very valiant defence, Les. But the giveaway is in your final sentence - Irish music is about tunes, unless it's songs. The best session I ever went to was at Hughes' pub in Dublin. A dozen people playing just tunes. No strummers, no harmonising, no goat-bashing. And no babble from the people in the pub either. A magical atmosphere. Irish dance tunes contain all the rhythmic drive already. Percussion is out of place in sessions. Do what you like with your bands and their arrangements. It can be fantastic, but that isn't what happens in most sessions.