Tuning? It's not easy. You've got 3 drone reeds. Those are the easy ones. Then you have a chanter reed, which is composed of two cane blades pressed and tied together with a small space between them. It's sort of the same concept as when you take a blade of grass and stretch it between your thumbs and blow. Air passing over the flexible surfaces causes them to vibrate, which creates sound. Once you have the sound, then you have to adjust it for each note on the chanter. Covering a hole on the chanter makes the chanter "longer", or at least lengthens the distance that the sound must travel before escaping into the environment. The farther the distance, the deeper/lower the tone. Cover all the holes and you have the lowest note, Low G. Since chanter reeds are made from wood/heavy grass (cane is sort of like bamboo) the surface is absorbent and reacts to heat and moisture. Your pipes might be in tune in the shade, but as soon as you walk into the sun all the notes go sharp on you.
Next, put 30 pipers together in a band and you've got a problem that sometimes takes weeks to solve. Some bands never solve it. But when it's right, it's great.
