1. Place an amplifier and a slide projector directly facing each other.
2. Fill the slide projectors carousal full of slides taken of the amplifier.
3. Run a microphone from the amplifier and place it on the top of the slide carousal.
4. Turn the amplifier on full volume and the slide projector on constant projection.
The slide projector will project the amplifier at the amplifier, and the amplifier will project the sound of the slide projector at the slide projector.
The sound and visual function in perfect harmony.