Insanely Fun DIY Science Experiments at Home with Physics Girl

I have a laser device that used 3 mirrors rotating at slightly different speeds/angles, that drew patterns like that on the wall, and also had a sound-to-light, which used the 3 separate audio (bass, middle, treble) as the source..
it also has an 'auto' mode which randomizes it..
Also, shine a laser onto a CD/DVD etc, and you get a similar 'dotted' effect from the reflection :)