20 HP · voice
Rain runs down the panel through its jacks, and a cable is a dam. The water pools behind it and every drop that lands rings a note, higher as the pool fills, until it breaks and floods down.
Turn a knob: drag it, roll the wheel over it or use the arrow keys; a double click puts it back. Dam the water: click a jack in the water to plug a cable into it, and click it again to pull the cable out.
example patches
The water, the dams and the notes here are RAIN's engine as it's designed, running in your browser: where each drop goes, when a pool breaks, what it rings. Everything round it is a stand-in for the rest of a rack.
Rain falls from the cloud under the big knob, and some lands here and there on the water. Each drop runs down the lit channels, round the stones and through the jacks either side of them, and out at the bottom corners. At a stone it goes left or right at random. A drop ticks as it lands, and rings the lowest note of each open jack it runs through, softly.
Plug a cable into one of the eight jacks in the water and it's a dam. The water stops there and pools, filling the ring round the jack from the bottom, then backing up the channel above it. Everything else goes round the other side. Plug both jacks on a row and there's nowhere left to go: it all backs up toward the stone. Pull the cable and the pool runs away.
When a pool holds DEPTH drops the dam breaks: the whole pool floods down at once, a white rush, into the next dam below that has a cable in. That can fill it and break it too, and its flood the next: a chain. The cables are still in, so each dam starts filling again.
In a light rain a pool can soak away before it ever breaks.
Every drop that lands in a pool rings a note, and the fuller the pool the higher it rings, like a bottle filling: a pool climbs a minor pentatonic scale, two octaves from empty to full, and a flood runs back down it over the rush of the water. Higher dams ring higher, the left ones on the left and the right ones on the right. Each note is struck glass, bright as it's hit and rounder as it rings.
Twenty HP, every part on the line's staggered grid and mirrored about the middle. The water runs down the middle three columns, a braid of bare circuit board lit from behind. The art is rings of gold dots spreading out from every dam, as rain spreads rings on a puddle.