Pinwheel

A drum kit that plays the picture as well as the sound. This is Roll Call's groove with a Link Out beside it, sending three LFOs, a swell on every kick, the bar and the drums' gates to Seoul, a music visualizer. Seoul's Obangsaek preset is a paper pinwheel in Korea's five cardinal colours, and in this patch it turns once a bar on the Clock, its colours breathe with the LFOs, and the kick, snare and hats each throw a bloom of colour into the wind.

Load it: choose 📚 Examples → Pinwheel in the toolbar and press ▶ Play. Then start Seoul and pick Obangsaek. The patch file is patches/pinwheel.json.

Or hear it here: press ▶ Play in the corner. The browser plays the drums, but only the desktop app sends to Seoul. The kit is Roll Call's; the Picture frame below the mix is what's new.

What it teaches

  • Cables play the picture. Link Out's lanes go to Seoul as cv1 to cv8 and gate1 to gate4, and a Seoul preset decides what each one moves. Choosing what goes into each lane is composing the picture.
  • The Clock leads both. Link Out sends the Clock's tempo and place in the bar with no cable, so the pinwheel turns on the patch's own bar, never on a guess.
  • Gates arrive as edges. A trigger lasts a fraction of a frame, yet every hit makes a bloom.
  • A preset for the link still plays without it. Close Soba and Obangsaek goes back to following what it hears.

The lanes

LaneFromIn Obangsaek
CV 1LFO, sine over 4 barsBlue, the east
CV 2LFO, triangle over 2 barsRed, the south
CV 3Slope on the kick: up at once, down over 0.4 sYellow, the centre, and the pin at the middle
CV 4LFO, sine over 1 barWhite, the west
CV 5Clock Divider's Count: a ramp through the barBlack, the north
Gate 1Kick laneA bloom
Gate 2Snare laneA bloom
Gate 3Closed hat laneA bloom
Gate 4Clock Divider's Trig: every downbeatA bloom

The LFOs have Bipolar off, so they send 0 to 1, and Obangsaek reads each as how much of its colour to show. Their phases are a third of a turn apart, so the colours take turns rather than swelling together.

Modules

Roll Call's fourteen, with these added:

ModuleSettings
Clock DividerDiv 16, Length 1: one count a 1/16 step, so a trigger every bar
SlopeRise 4 ms, Fall 0.4 s, Shape -0.5
LFO (blue)Tempo 4 bars, Sine, Bipolar off
LFO (red)Tempo 2 bars, Triangle, Phase 120°, Bipolar off
LFO (white)Tempo 1 bar, Sine, Phase 240°, Bipolar off
Link OutPort 9137

How it's built

[Clock Gate]  ──> [Clock Divider Clock]
[Clock Reset] ──> [Clock Divider Reset]
[Trigger Sequencer Gate 1] ──> [Slope Trig]
[LFO (blue) Out]  ──> [Link Out CV 1]
[LFO (red) Out]   ──> [Link Out CV 2]
[Slope Out]       ──> [Link Out CV 3]
[LFO (white) Out] ──> [Link Out CV 4]
[Clock Divider Count] ──> [Link Out CV 5]
[Trigger Sequencer Gate 1, 2, 3] ──> [Link Out Gate 1, 2, 3]
[Clock Divider Trig] ──> [Link Out Gate 4]

Nothing in the Picture frame reaches the Audio Output, so the patch sounds just as Roll Call does.

Seoul's side

Seoul listens on port 9137 unless its seoul.toml says otherwise. Link Out's lamp turns green once Seoul is listening, and amber, with no Seoul, while nothing is. Seoul's F1 panel shows the link: eight CV columns, four gate lamps, and conf link beside the tempo while the Clock plays.

The picture gets the lanes sooner than Seoul hears the sound, which goes the long way through your audio device. If a bloom comes before its drum, raise delay_ms under [link] in seoul.toml until they land together. 40 ms is a good start.

Try this

Another preset. The gates follow Seoul's lane convention (kick, snare, hats, downbeat), so the patch plays more than Obangsaek. Try Han River, where the kick surges the fountain and the snare sets off fireworks, or Hongsalmun, where each kick is a stride through the gates. In Gayageum, each CV lane bends one of its strings and each gate plucks one.

A colour from the music. Patch an Audio Input's Follow into a lane in place of an LFO, and sing the colour in.

Faster colours. Set the LFOs' Tempo to 1/2 or 1/4 and the pinwheel's colours flicker on the beat.

Stop and start. Turn the Clock's Run off: the pinwheel stops following the bar and Seoul goes back to finding the beat by ear. Turn it on again and it locks back on.