Slowtide

How the translation works

Five readings off one drawing

1. Span → pitch.The figure's overall size sets the fundamental. A wider mark in the crop sounds lower, the way a longer string or a larger plate does; a hand-sized amulet rings up in a higher register than any field.
2. Symmetry → harmony.N-fold rotational symmetry lifts the Nth partial and its multiples — the same partials a plate divides into when it carries N nodal diameters.
3. Rings → timbre.Concentric bands in the design push energy higher or lower in the partial stack, giving each figure its colour. Where a figure encodes numbers — the digits of π, the Horus-eye fractions — those numbers are used as the partial amplitudes directly.
4. Lay → attack.A swept, spiral lay rolls the upper partials off gently and warm; a hard geometric lay keeps them bright and present.
5. Then the plate.The figure's sound drives a round plate scaled to its span. A round plate can only hold still along spokes and rings — the crop-circle family — and the tone is set where the mode that shares the figure's symmetry resonates: six spokes for a six-fold formation. The partials add fainter lines. So the sand rhymes with the figure without copying it: it is the shape of the figure's sound, computed as a real forced vibration.

Raise your own. Pick Your own tone at the end of the strip. Then both plates stop following a figure and follow sound. The model is a driven plate's: each mode responds with amplitude 1 / (ω_k² − ω² + i·2ζω_kω), so whichever modes sit nearest each spectral peak carry the figure, and it morphs continuously as the pitch moves rather than jumping between pictures. Square-plate modes go as m² + n² (bending stiffness); the circular plate on the left uses Bessel-function modes with a free edge — rings and spokes, the crop-circle family — drawn as flattened crop. Drag the tone slider and play, or use the microphone and sing, bow, or play a record: several notes at once excite several figures, and you see their sum.