The Storm by Jack Pavlik
The Storm by Jack Pavlik is a great example of using the characteristic sound of a specific material without a lot of machinery. There's just one band of spring steel, rocking back and forth, powered by a single motor. As you can see the movements are small, yet the sonic effect is overwhelming.
Jack Pavlik made more installations with multiple bands, but I find this one to be a great example of effective use of some basic material. The characteristics of the sound create the feeling of an upcoming storm. The shadows on the wall make it a beautiful thing to look at.