color notation system &
visual music instrument

Sound and color, being different by their nature,
merge together on the surface of our consciousness.


Electromagnetic radiation consists of synchronised oscillations (or their quanta, photons) of the electric and magnetic fields, propagating through space at the speed of ~300,000 km/s. Visible light is a certain portion of electromagnetic spectrum between infrared (too weak to excite electrons in molecules) and ultraviolet (powerful enough to cause irreversible chemical reactions in organic matter).


The main source of light on Earth is the Sun. Thermonuclear reactions in it’s core produce high energy gamma-rays that are absorbed and converted into lower energy radiation by ionized atoms in it’s photosphere and chromosphere layers. After traveling through space for about 500 seconds (8 m 20 s) it reaches the Earth, where the atmospheric gases absorb x-rays, most of UV and some of infrared spectrum. The remainder reaches the surface of the planet being partly scattered by air molecules. This elastic scattering is stronger for light with higher frequencies and results in the blue glow of the sky and red color of the sunsets.


The perception of color derives from the stimulation of cone cells in the human eye by visible light. Light, containing all spectral colors is perceived white. Color of an object depends on the range of wavelengths of light that are absorbed or reflected by it’s surface. The sense of a particular color is produced in nervous system by combining signal from three types of cones, sensitive to red, green and blue ranges of the spectrum.


Acoustic vibrations propagate as mechanical waves of pressure in a transmission medium such as gas, liquid or solid. The speed of sound in air at 20 ºC is about 343 m/s (1,235 km/h) and complexly depends on density and pressure/stiffness of the medium. Audio range falls between infrasonic (<20 Hz) and ultrasonic (>20 kHz) frequencies. Sound is amplified and transformed into nerve signals by mechanically activated hair cells emitting glutamate neurotransmitter in a basilar membrane in the cochlea of the human inner ear. It happens in a spiral organ with 2.5 coils of tonotopically organized bone tissue resonating with different frequencies in it’s different locations.

Frequency, Hz
Amplitude, px


Human auditory system represents information about different characteristics of the sound. Slowest vibration of the sound gives us a sense of a particular pitch, while spread and intensity of overtones over time build up the feeling of timbre and overall sound pressure and complexity give us a sense of it’s loudness. Cognitive separation of auditory objects builds sonic texture and differences between signals from two ears help recognise spatial location of the sound in an environmental context.

Circle of colorfull notes

A is the lowest frequency note and red is the lowest frequency color. It’s the starting point. Then we divide the light spectrum into 12 parts and get scientifically correspondent colors for every note in an octave. Now we can see the circle of musical intervals with our eyes and use it to remember all the musical semitones.

{{time}} {{(frequency*num).toFixed(2)}} Hz {{i}} 1/{{num+1}} {{col}} 1/{{num+1}}
Front waves
Back waves
Standing waves
Combine waves
Frequency, Hz

Harmonic series

Acoustic oscillators such as a string or a column of air vibrate at numerous modes simultaneously. Waves travel in both directions along it, reinforcing and cancelling each other to form standing waves, that produce audible sound in surrounding air. The longest allowed wavelength of an oscillator is twice it’s the length. Wavelengths that are 1/2, 1/3, 1/4, 1/5 1/6, 1/7, etc. times that of the fundamental are members of it’s harmonic series. They form an arithmetic series (1×f, 2×f, 3×f, …) of frequencies with constant difference equal to the fundamental.


Any two musical notes with fundamental frequencies in a ratio equal to 2n (n is any integer) are perceived as very similar and represent the simplest interval in music – an octave. Human pitch perception is periodic so that “color” or chroma of all the notes that are an octave apart seem circularly equivalent and brings them together into one pitch class.

{{notes[i].name}} {{tunings.just.values[i]}}

12-Tone Equal Temperament

(3/2)12 ≈ 129.74634 ~ 128 = 27

Useful music apps

High quality vinyl keyboard stickers

We design and produce vynil sticker packs for different music instruments. You can use them as an educational tool, or just add some colorful associations to your well-known note sounds!

And don’t forget about the new cheat sheets! Always have the most important musical knowledge along with your colorful keyboard. Explore all the major and minor keys and their chords with only one small but durable piece of laminated paper.

Projects that use Chromatone

tsoop is a collaborative music improvisation project


Denis Starov

Moscow, Russia