Hi Herge

Pipers chords are played on using the parallel tubes that lie across the piper's knee (I think its the drones that are used, that generally provide that droning noise that accompanies the tune) On some pipes, 3 or so of these tubes have 4 or 5 keys along their length which cover holes. These keys are arranged in line so that a piper can use the edge of his hand to press down one key on each of the tubes all at once, while he is also playing the tune on the chanter. I think that these keys are called regulators. He is therefore restricted to the notes that the keys allow him to play, and the notes whose keys he can reach while he is playing that particular part of the tune.

I've just looked around my house for a tutor book on Irish pipes so that I can check the names and found them for northumbrian, Scottish mouth blown pipes, Scottish bellows blown pipes, border pipes, every sort of pipe but Irish!

So basically the chords played by Irish pipers are the chords that are part of their instrument. If it's a piping tune being played by a piper, they are the chords that belong to the tune, in my opinion.

Hope this helps, Liz