This is the Singing Ringing Tree. I like this a lot.
Via the YouTube page:
The Singing Ringing Tree is a musical sculpture situated at Crown Point above the town of Burnley, Lancashire, United Kingdom. It is one of a series of “Panopticons” in the Lancashire Pennine Hills. It was created by artists Mike Tonkin and Anna Liu and completed in 2006. This video is primarily intended to give an impression of the sounds created by the wind interacting with the sculpture.