A macro is a knob you invent. Declare it once, wire it anywhere, and it appears in the rack on the left — live, MIDI-mappable, and automatable by the song.
bright = macro "bright" 0.5 declares a knob named bright, initial value 0.5, range 0–1. It's a control signal like any other.
Wire it with arithmetic: cutoff = const 400Hz + bright * 4000Hz. Drag the slider while the pattern plays — you're mixing the sound live.
One knob can drive many destinations at different depths: add + bright * 0.2 to the gain and brightness now also means louder, like a real instrument pushed harder.
A macro can carry its own motion: a third argument (macro "air" 0.4 (lfoSine @ 1/2c |> scale [0, 0.3])) sums a modulation graph on top of the knob — the knob sets the center, the LFO breathes around it.
The starting point#
The lesson opens with this song in the editor. Every edit recompiles and plays.
-- Macros: the brightness is hardcoded. Put it on a knob you can play.
keys = patch {
source = saw (freq pitch),
ampEnv = adsr 5ms 200ms 0.4 200ms,
cutoff = 2400Hz,
gain = vel * 0.4
}
comp = play keys !"c3 eb3 g3 <bb3 c4>"What to watch#
Turn your knob in the rack on the left while it plays — the spectrum moves under your hand, with no edit and no recompile.
Goals#
The workbench checks these as you work; the solution is there when you want it.
- Declare a knob
- Wire it into the sound
- Stretch: give a knob its own motion
Make it yours#
Design one "performance" knob that changes at least three things at once — cutoff up, reverb-ready gain up, attack down — so a single gesture takes the patch from asleep to awake.
Further reading#
Macros and automation in the reference.