Roppongi Hills is a leviathan of a property development in eastern Tokyo, encompassing apartments, restaurants, office space, cinemas, a museum and amphitheater, a TV studio and hotel, a few scenic parks and a 54-story highrise that's shared by several international corporations.
Having opened its doors in April 2003, the urban center is now passing through its 10th anniversary. The company that erected it, Mori Building, has decided to mark the occasion with an online artwork that matches Roppongi's grandness with suitably impressive audio-visual glory. "Tokyo City Symphony" is an interactive music video featuring shifting patterns on a simulacrum of the development; by mushing their fingers on the keyboard, people can compose their own strange songs and make Roppongi spangle like a jukebox energized by magical rainbows.
Mori's creative crew achieved these far-out effects by fabricating a 1:1,000-scale miniature of Roppongi and then painting it with video-mapping projectors. Players can choose between three graphic themes to give the "songs" different flavors – the most interesting one, I think, is the "Edo City" option that riffs on cherry blossoms, fireworks and other cultural stuff. They all basically look like Timothy Leary tried to re-remake Tron, though: