Planetary Keys

This is something I made in anticipation of a similarly constructed robot controller for The keys were designed in Inkscape and printed onto cotton letterhead, then painted over with Bare Conductive paint (you could just paint the keys; I am not a terribly good painter, so I like to design on and print from a computer). I connected them to MaKey MaKey, which lets you turn pretty much anything that conducts even small amounts of electricity, into a button or switch that is interpreted as a keyboard or mouse action on a computer. I wrote a Processing sketch that reads each key and displays a corresponding color and plays a corresponding note. The black, shungite pyramid is conductive and connected to the ground part of the circuit, so when I touch the pyramid (with my right hand, in the video) and also one of the keys, I pull some of the electricity through my body to ground — enough for MaKey MaKey to recognize which connection I have altered, and activate the appropriate output.

(I have only six of the seven keys wired in the demo video, because more would have required the addition of a mouse action, and I just wanted to keep it simpler than that, but it is possible to use all seven.)

The correspondences I used are from Paul Foster Cases‘s Correlation of Sound and Color (you can find PDF copies online); there are others. If you are interested in his sources, Alison Deadman wrote an excellent article about them: “Letter, Musical Pitch, and Color in the Work of Paul Foster Case” (links to PDF). Dr. Deadman teaches music history and Alexander Technique at East Tennessee State University.

I have imagined many uses for this technology; a variety of ritual interactions. E.g., a conductive talisman that “charges” the magician when she completes a circuit by touching the talisman with one hand and an earthed device (metal stang?) with her other — perhaps triggering lights or video, music or other sound. Or printed/painted psionic devices. Etc. Feel free to share your own ideas in the comments.


TAD2011.03 Planetary Color Grid

Third TAD project. I intend to use the 2D array in future sketches.

Planetary Color Grid

Source code:

 * PlanetaryColorGrid
 * by Joshua Madara,
 * This project displays a grid of the planetary colors
 * for each hour * day of the week, per "Table of the Planetary 
 * Hours" from the "Introduction" to Mathers' _The Key of 
 * Solomon the King_. The colors are specified in the 
 * same book: "Table of the Archangels, Angels, Metals, 
 * Days of the Week, and Colours Attributed to each Planet."

// set color for each planet
color MER = #800080; // Mercury, Purple
color MOO = #FFFFFF; // Moon, White
color SAT = #000000; // Saturn, Black
color JUP = #0000FF; // Jupiter, Blue
color MAR = #FF0000; // Mars, Red
color SUN = #FFFF00; // Sun, Yellow
color VEN = #008000; // Venus, Green

// create 2D array to store color by hour (row) and day (column)
color[][] TBL = {

// variable x and y positions for each square in grid
int xPos = 0;
int yPos = 0;

void setup() {
  size(70, 240); // columns * 10, rows * 10
  noStroke(); // fill only
  noLoop(); // draw once

void draw() {
  yPos = 0;
  for(int i = 0; i < 24; i++) { // for all rows
    xPos = 0;
    for(int j = 0; j < 7; j++) { // for all columns
      fill(TBL[i][j]); // set color of square
      rect(xPos, yPos, 10, 10); // draw square
      xPos += 10; // move to draw next column
    yPos += 10; // move to draw next row


This is a Processing sketch that returns colors and sounds corresponding to the astrological signs of the zodiac, in a fairly direct (and probably underwhelming) way. I have some ideas for developing more creative interactions, but for here and now I am documenting the correspondences and some simple code to interact with them.


Click the image to run the sketch in your browser (requires Java and JavaScript), or follow this link if that one is giving you trouble. You can view the source code here.

Below is a table of the correspondences I used and took from Case‘s Correlation of Sound and Color [1], which as far as I know he inherited from the Golden Dawn and the King Scale of Color.

Index Sign Color Dec Hex Sound Freq
1 Aries Red 255,0,0 FF0000 C 261.63
2 Taurus Red-Orange 255,64,0 FF4000 C# 277.18
3 Gemini Orange 255,128,0 FF8000 D 293.66
4 Cancer Orange-Yellow 255,192,0 FFC000 D# 311.13
5 Leo Yellow 255,255,0 FFFF00 E 329.63
6 Virgo Yellow-Green 128,192,0 80C000 F 349.23
7 Libra Green 0,128,0 008000 F# 369.99
8 Scorpio Green-Blue 0,128,128 008080 G 392
9 Sagittarius Blue 0,0,255 0000FF G# 415.30
10 Capricorn Blue-Violet 64,0,192 4000C0 A 440
11 Aquarius Violet 128,0,128 800080 A# 466.16
12 Pisces Violet-Red 192,0,64 C00040 B 493.88

The Colors

(The capitalized color names in the following paragraph refer to HTML color names. The mixes I made with this HTML color mixer.)

I had some options while mapping Case’s colors which were based on the RYB (subtractive) color model, to the RGB (additive) color space. I chose Green (008000) instead for Lime (00FF00) for green, and the middle of Red (FF0000) mixed with Blue (0000FF) for violet (= 800080, i.e. Purple), instead of Magenta (FF00FF). I could have used Aqua (00FFFF) for green-blue, or mixed Blue (0000FF) with the darker Green (008000) (= 004080), but instead chose the middle of Blue (0000FF) mixed with Lime (00FF00) to make my green-blue (008080). To make orange (FF4000), I used the middle of Red (FF0000) and Yellow (FFFF00).

If you have any ideas about the color correspondences in RGB/CYM space, please leave a comment below.

The Sounds

The sounds are generated by a monotone sine wave. I got the frequencies for the musical notes from this page.

Notes & References

  1. Paul Foster Case, Correlation of Sound and Color (Boston: The Hestia Publishing Co., 1931).