Light Play was built for Toronto's annul Arts and Creativity Festival, Luminato in 2008.  Light play is a take on a 1950's dance hall. The orbs react change color and react to the sounds of the audience and live music. Over 1,000,000 people attended the free festival and participated in dance lessons.

Source material: http://www.contemporist.com/2008/11/14/light-play-at-luminato-by-michael-levine-and-kpmb/