ADSR
- Attack: time to reach the maximum.
- Decay: time to fall to the sustain level.
- Sustain: level held while the key is pressed.
- Release: time to die away after release.
Archetypes (indicative values)
- Pluck: A 0–5 ms, D 150–400 ms, S 0%, R 100–300 ms.
- Pad: A 300–1500 ms, long D, S 70–100%, R 1–3 s.
- Lead: A 5–20 ms, high S, R 100–300 ms.
- Stab: A 0, D 100–200 ms, low S, short R.
- 808 / long bass: A 0, very long D or full sustain, short R so as not to muddy the changes.
Filter envelope
With a second envelope on the cutoff, the sound changes color over time: short decay + high amount = bright attack that closes (funk basses, plucks); slow attack = a sound that opens (brass, evolving pads). Assigning velocity to the envelope amount makes the sound expressive.
Relationship with tempo
At 120 BPM an eighth note lasts 250 ms and a sixteenth note 125 ms: a pluck with a 200 ms decay sounds rhythmic on eighth notes, one with 600 ms smears them. Set the decay to the rhythm of the part.
LFO
- Vibrato: LFO on pitch, 5–6 Hz, depth 10–30 cents.
- Tremolo: LFO on volume.
- Wobble: LFO on the filter synced to tempo (1/4, 1/8, 1/8 triplet): dubstep and bass music.
- Sidechain-like pulsing: LFO on volume with a ramp shape synced to the quarter notes.
- Slow movement: LFO at 0.1–0.5 Hz on PWM or filter for lively pads.
Glide
Portamento 30–150 ms in mono legato mode: slides between lead and 808 notes (drill, trap).
Real-world example
“Scary Monsters and Nice Sprites” by Skrillex (2010) made modulated dubstep basses iconic: filters and timbres moved by LFOs and envelopes synced to the tempo.