'Color a Sound' turns projector transparencies into sheet music

Boy, something like this would have made class a lot more interesting — and musical. Blair Neal's "Color a Sound" uses transparent sheets (just like teacher used to use) sliding across an overhead projector to act as sheet music, while the different colors and shapes of markings act as the notes. You control the tempo yourself with a crank, and the projector-boombox can even change to making drum beats for something a little funkier.