Strange musical(?) sounds in Milton Keynes (Ray Lee's "Chorus")

During a meeting this morning, I could hear some strange noises outside - on my way back to the car, I had to investigate. It turns out that it was coming from a sound scultpure, part of the Milton Keynes International Festival - (http://www.ifmiltonkeynes.org/festival-programme/2014/07/21/ray-lee-chorus.html) There's a lot more to see and hear there - just a shame I had to get back to Stinky Watford for work..