Thanks, Mr Codger. You are demonstrating a load of theoretical "knowledge" when we all know that the proof of the pudding is in the eating. If you sit in a session all night playing chords, good luck to you. You wouldn't last ten minutes round here doing that. Most harmonica players I've met who do that do it because they're not very good at doing tunes. I'm sure that you're quite possibly an honourable exception. Melodies is what Irish music is all about, not chords, old chap.