The prototype is the circuit on a breadboard and a small LED array.
I am still fine-tuning the circuit, and obviously once I do I'll solder it to a perfboard to make it permanent.
However, right now I just wanted to show it off, especially the frequency dependency of the LEDs.
It is far from finished, the final product won't just have 4 LEDs flashing.
No microcontrollers were used in this project, though it probably would be a heck of a lot easier if I had used a microcontroller.
Video follows, cheers.
The Colour Organ (Video):