It's one thing to have a crazy idea - it's another to make it happen. I'm so impressed by people who do. Usually, we call them artists.
John Cage was one, and he constantly pushed the boundaries - what is music? what is silence? How slow is slow?
His organ piece "As SLow aS Possible" was debuted in a 29 minute performance. But at a church in Germany, a performance of As SLow aS Possible began in 2000, and won't finish for another 631 years. If you want to hear the next chord change in the piece - an occurrence roughly as frequent as a lunar eclipse - you'll need to get to Halberstadt, Germany by November 5. If you miss that one, you'll have to wait until February, 2009.
There's no reason to do something like this. That's what makes it so fascinating to me.
You can read about it at the Long Now Blog - always worth a look.
Apparently, this piece didn't make it into the popular canon - amazon.com doesn't even sell a recording of it.