Art-Music Project

Blog about project to convert between music and visual art by Robert Dawson

Mapping of color to sound

Music is governed by harmony, whereas visual art can be appreciated with a much looser application of visual stimuli.

On the chromatic scale, doubling the frequency of a pitch increments by one octave. For example, note A4 is 440 Hz, so A5 is 880 Hz.

Since sound requires such precision to be appreciated as music, we can apply this doubling rule to color to achieve a harmonic conversion. The spreadsheet below shows this mapping.

Color-sound mapping

I still have a lot of work to do. For example, color frequencies increase well beyond the range of the basic colors. I'm hoping this can equate to light or dark versions. 

Essential equation to convert color to sound

On the chromatic scale, pitch is divided into 12 equal parts to make an octave. Also, doubling or halving the frequency of a pitch adds or subtracts an octave, respectively.

The mathematical equation for this is the multiplication or division of a given frequency by the twelfth root of two.

Since I'm using a Google Docs spreadsheet to compute frequencies, this equation can be written as a formula to automatically find the next or previous value, like this:

=(n-1)*2^(1/12)

or

=(n+1)/2^(1/12)

Source

Note: (n+1) and (n-1) represent a next or previous cell's name, respectively, like F88 or F86 when applied to F87.

Since there are 88 keys on the keyboard, if I start with Key 1, called A0 in musical notation, then I can use the second formula above to find Key 2. Once I know that, I can find the remaining 86 keys with the first formula.

Of course, this assumes that I already know the frequency of one key or pitch. But we (meaning humans) have scientifically measured them all through experimentation, so the problem is simply finding how to write the equation as a formula in Google Docs (and presumably Excel).

In my next post, I will show the mapping of color to sound by using these formulas.

Color analysis

Tonight, I made a color analysis, comparing RGB, HSV, and hex values. Included are two sets of colors. One contains primary and secondary colors, giving the famous ROYGBIV minus the I or indigo. The other set is the first plus additional colors to fill in the gaps and give a 30° distribution.

Observations 

  • Green at #00FF00 looks more like lime green. #008000 better resembles what I think of as "true" green.
  • An even V(alue) distribution results in a lot of green! Therefore, I surmise that the plant world turned green to appear popular among lifeforms, especially given that they can't really move on their own for the most part.