Metallic Spheres, originally released in 2010, is a collaboration between ambient house group The Orb and Pink Floyd guitarist David Gilmour, produced by Youth of Killing Joke, who also played bass. The project grew out of a remix The Orb made of Chicago/Change the World, a benefit single for the hacker Gary McKinnon. Gilmour recorded his guitar parts in a single day at Youth's studio, The Dreaming Cave. The album consists of two long suites, Metallic Side and Spheres Side. The artists' royalties went to supporting McKinnon.