Ok, you're a Pentagon scientist, you've got three years to spare and you enjoy tapping stalactites in your local cave complex. You're fascinated by the tones they produce and you want to put your years of maths and electronics experience to use for the power of good, not evil. So what do you do? You build the world's largest musical instrument, of course. It's an organ that chimes its notes on hand-selected stalactites in the surrounding three and a half acres of caves. And the best bit? It's called the Stalacpipe!