Interesting points made here. Some tunes are great for playing lots of times, especially planxties and slowish waltzes. It's great fun to play variations, harmonies, swap in and out instruments and so on. I've sometimes referred to these as 'last one with the tune is a sissy!' It's fine for those players who are just learning the tune (or an instrument) as they get lots of goes, and it's fun for players who can do variations and harmonies. I'm not sure it would be so much fun for players who are midway, though - that is they can play the tune well enough but can't move too far away from it. Just playing the same old notes again and again isn't really that interesting (unless it brings on the trance effect mentioned by JK). But that could be counter-productive anyway. Will publicans still allow us the use of their premises if we never stop playing to go to the bar, and we achieve the desired effect without the use of their stock in trade? (hehe)

The point about tunes in sets is that some tune sets are wonderful in the way that one tune builds on the previous tune to take the music further on. Play 'The Tar Road to Sligo' after 'Tripping up the Stairs' (as we do here in East Yorkshire) to appreciate this. Playing a random set of reels or jigs doesn't really do it for me, but a nicely organised set is a work of art.