What a color sounds like

Visible light runs 384–789 THz. That is a ratio of 2.05 — the entire rainbow is one octave. Drop it by forty octaves and it lands almost exactly on F4 → F5, close enough to play.

vol

The lightspectral power, 380–780 nm

The soundthe same axis, as piano keys

Roughness

Drop by 2⁴⁰ Stretch 1× 1× is the true mapping. Anything more is a lie that lets you hear inside it. Oscillators 48 How finely the spectrum is chopped. The instrument, not the physics. Humps only Play one tone per hump instead of the whole band — the tidy version.

Two whites

identical to the eye, nothing alike to the ear

Your screen makes white from three narrow emitters. The second spectrum below is one smooth hill — and it is not nearly the same colour, it is exactly the same colour: three broad humps solved so their XYZ matches the screen's to the last decimal place. Your eye reduces any spectrum to three numbers and discards the rest, which is the whole trick that lets screens work at all. Your ear discards nothing. Play them.