The elevator installation at the Ars Electronica Center features an application that simulated a virtual space underneath the elevator inhabited by sonic particles.

The system reads the height of the elevator and translated it to the OpenGL environment, so that the space was a one to one mapping. To the viewer it appeared that they were looking down through a glass floor at the lift shaft below. At the basement level one particle bounces around the space. As the elevator rises that particle gives birth to two particles, which in turn give birth to another two etc. By the time the elevator reaches the top of the Center, 64 particles are bouncing around the space. Each time a particle hits a wall or the floor of the elevator it briefly lights up the space and produces a sound whose pitch corresponds to the height at which it hits. So as the elevator rises the particle system creates increasingly complex musical patterns. When the elevator returns to the basement the particles return to their parents and disappear, leaving the lone particle again.

A work by Theodore Watson.
Video.
Picture courtesy of the artist.