efrafa

36 HP · pattern sequencer

A drum pattern that lives, breeds and dies, and you play it with your fingers. Six rings of sixteen lit cells are a bar of six trigger lanes, and every few bars the warren turns: one generation of Life. Hold the cells you want kept, and the groove stays while everything round it changes.

The EFRAFA panel: black, with a wall of earth in gold dots, pale roots hanging down through it round a round hollow in the middle. In the hollow, six rings of sixteen small windows of bare circuit board, the warren, and the BREAKOUT button at its heart. RATE, MARK, LENGTH and REPEATS to its left, RULE, WIDTH, MUTATE and DENSITY to its right; the jacks SHIFT, CLOCK, TURN and PITCH down the left edge, BREAKOUT, RESET, WILD and HRAIR down the right, and the six outs along the foot. efrafa at the top, daylight noise at the bottom.

Turn a knob: drag it, roll the wheel over it or use the arrow keys; a double click puts it back. The warren: click a cell to plant or kill it, drag round a ring to draw, drag out along a spoke to clear it, press and hold to hold it; a right-click or three fingers clear all but the held; or tab to it and use the arrows and Space. BREAKOUT is a button to press. The patches step on by themselves until you touch anything.

The warren and its lights are EFRAFA's own. The kit its rings play (ring 1 the kick, out to the open hat), the bass, the glass, the crash and the pad round it are made in the page as you listen.

example patches

The warren, its law, the touch and every out here are EFRAFA's engine as it's designed, running in your browser. The clock, the kit, the bass, the glass, the crash and the pad are a stand-in for the rest of a rack.

The warren

A ring is a lane with its own trigger out, a spoke is a step, step 1 at twelve o'clock. A hand sweeps round on the clock, and every live cell it passes fires its ring. The bar plays REPEATS times, then the warren turns: one generation of Life, each cell born, kept or dying by its eight neighbours, wrapped round both ways.

Holding

Keep a finger on a cell for half a second and it's held: red and steady. A held live cell can't die, and nothing is born on a held empty one, a rest, which glows a faint red. Hold it again to let it go; nothing else touches it.

So you draw the backbone, the kick on 1 and 9 and the snare on 5 and 13, hold it, and Life breeds and dies round it: ghost notes, fills, hats. The groove survives.

Marks

Only the part of the bar that's out may change at a turn. The rest stays as it is, under curfew, dimmer, though its cells still count as neighbours. Empty cells in the part that's out glow faintly.

Breakout

Press BREAKOUT, at the warren's heart, or send a gate to its jack, and at the next bar line the warren turns with the law lifted: nothing under curfew, and the held cells free to die like any other. At the bar line after, every held cell is back where you put it. A fill on demand that always comes home. Hold the button or the gate and it turns free every bar until you let go.

The law

What comes out