John Cage's composition "4'33"" famously includes not a second of sound — at least, not from any of its performers. The piece is meant to draw attention to the sounds happening all around you, and a new app from the John Cage Trust will let you experience the rich ambient sounds being made across the globe. Released for iOS earlier this month, the 4'33" app allows you to explore a map and listen to the composition as it's been recorded by users of the app worldwide. There are already dozens of...
