A piece of sound art that stood out to me was Lines which was created in 2016 by composer Anders Lind. The installation is a series of lines on the floor, walls, and hanging down from the ceiling that can be interacted with by the audience to make different pitched sounds. I was really drawn to how participatory the piece is, I love it when art is accessible to its audience and promotes discovery in its viewers. It is also great in how it can be a group experience with people creating music together as well as a solo one.
I would think that the algorithm for this piece would use motion sensors to determine how far away an obstruction is and to play a certain pitch/tempo per distance.