Spanish designer Guillermo Lorenzo created this interactive installation:

Interactive audio-visual intalation. where the players can modify sound by placing pucks on virtual tracks on two tables. One of the tables is singing "hap hep hip hop" while the other serves as a mixing table. The visitors move the pucks on the table, which is divided into square regions. Each square senses the amount of light that is left through the objects, the more objects the more sound can be heard.