Sound frequencies are displayed as they are heard. Lower frequencies are mapped low (bottom) to high (top). Brightness is determined by amplitude.
Sweeping tones and rhythmic patterns create intricate structures. The circular form is in memorial of dead formats; the CD, MiniDisc and others. R.I.P.
Here’s a Leesa’s The Mansion run through Spectrogram:
Built by Lee Martin (Soundcloud developer), using
<canvas> and the Soundcloud API.
(add any soundcloud track URL to the URL to see that track visualized)