There seem to be versions of bagpipes from all around the world, but I thought that the main feature that made the uilleann pipes special was the regulators which make it possible to play the drones as well as the chanter. Do any other pipes around the globe have this innovation and exactly when did it evolve - I thought that it was a fairly recent addition. Incidently are bellows-blown bagpipes common outside the British Isles ?