I thought this was VERY cool and I wanted to share. I guess they traveled all over the world, and recorded a bunch of street performers and choirs singing the same song and then edited it all together so that they were harmonized.
This is the website, go to it and click the Journey tab and watch the video of the guy talking about the project:
http://www.playingforchange.com/journey/introduction
There are more videos on the website too; the two I am posting are my favorites.
