The heartbeat of dance music: every kick, the pads duck out of the way and swell back. In Volta that's not a plugin — it's one line of arithmetic.
follower "kick" 10ms 120ms listens to the kick TRACK and outputs its loudness envelope — a control signal that jumps on every hit and falls back over 120ms.
Build the duck in three pieces before you write it. ONE: that follower is a number between 0 and 1 — near 0 between kicks, rushing toward 1 on each hit. TWO: const 1 - it turns the bump upside down, so the signal rests at 1 and dives toward 0 exactly where the kick is — a kick-shaped hole in time. THREE: multiplying a gain by that hole makes the gain fall into it. That's ducking: no plugin, just arithmetic on a control signal.
Assembled, with a depth and a level: gain = (const 1 - follower "kick" 10ms 120ms * 0.8) * 0.4. The * 0.8 before the subtraction sets how deep the hole goes (80%, not total — breathing rather than stuttering); the outer * 0.4 is the pad's ordinary level.
The release time (120ms) IS the groove: short = tight tick, long = the classic French-house wallow. Tune it while it plays.
Any control slot ducks, not just gain — subtract the follower from the cutoff and the pads darken on each kick instead of just quieting.
The starting point#
The lesson opens with this song in the editor. Every edit recompiles and plays.
-- Sidechain: kick and pad occupy the same space, nobody yields. Make the pad duck.
pad = patch {
source = saw (freq pitch) + saw (freq pitch + 7Cents),
ampEnv = adsr 120ms 0ms 1 300ms,
cutoff = 1100Hz,
gain = vel * 0.4
}
kick = sound !"bd bd bd bd"
pads = play pad !"c3 ~ ab2 ~"What to watch#
The pump is visible: on every kick the whole waveform is squeezed toward the centre line, then swells back before the next one.
Goals#
The workbench checks these as you work; the solution is there when you want it.
- Listen to the kick with follower
- Duck the pad's gain with it
- Play it and feel the pump
- Stretch: duck the colour too — the cutoff dips on every kick
Make it yours#
Sweep the follower's release from 60ms to 400ms while it plays. Somewhere in there is YOUR genre — stop when you feel it.
Further reading#
Make one sound follow another in the reference.