Sound Visualization: Notes, Chladni Figures and a Color Organ Online

No. This is a model of a square plate: the figure is chosen by the pitch of the leading note, and the grains move by the same rule as real ones — they jump where the plate shakes and stay on the lines that do not move. A real plate has its own resonant frequencies, which depend on its size, thickness and metal, so the same frequency draws a different figure on it.

In “Opticks”, Newton laid the seven colors of the rainbow on the seven notes of the scale: C is red, D orange and so on up to a violet B. In the light part of “Prometheus”, Scriabin arranged colors along the circle of fifths: C is red, G orange, D yellow, A green. So with Newton neighboring notes are close in color, and with Scriabin notes a fifth apart are.

Yes, with the “Tab” source: the browser asks what to share — choose the tab and check “Also share tab audio”. This works in Chrome and Edge on a computer; Firefox and Safari do not hand tab audio to a page, and phones have no such option — there the microphone and a file remain.

The line shows one note, the most prominent one. For a single voice, a flute or a violin it is found reliably; when many notes sound at once, the most prominent is now the bass, now the vocal, now the chord. All the sounding notes stay in the picture as colored tracks — the line is only a hint of what to follow.

No. This is the signal level relative to the recording limit (dBFS): 0 dB is the loudest sound the input can pass without distortion, silence is around −60 dB and below. Loudness in the room, in decibels of sound pressure, also depends on the sensitivity of the microphone, and that differs from device to device.

It turns off the brief full-screen flashes on strong hits, slows down the spotlights of the color organ and changes the patterns in sand and water less often. Even without it, flashes come no more than three times a second, but people who are sensitive to flicker are more comfortable with none at all.