dynamics

• dynamics covers effects that change continuously or stochastically while a note is sounding
• unlike envelopes (fixed per-partial shapes) or decorators (static per-partial tweaks), dynamics vary over time

• each dynamic behaviour is built from two layers:

  • an effect family (what processing occurs)
  • a progression family (how its intensity evolves across the note)
• every family exposes two parameters a, b ∈ [0…1], remapped to musically useful ranges

• id 0: slow spectral morph

  • behaviour

    • cross-fades the current amplitude distribution toward a target amplitude or frequency shape

  • notes

    • supports morphing between any two distributions
    • smooth continuous transition

  • parameters

    • a = morph depth (0 = no morph, 1 = full target)
    • b = morph rate (0 = spans whole note, 1 = completes in first 10% of note)

• id 1: gated band-pass

  • behaviour

    • applies a band-pass filter that opens and closes according to progression

  • notes

    • isolates part of the spectrum in rhythmic or stochastic windows

  • parameters

    • a = band centre frequency (0 = fundamental, 1 = nyquist)
    • b = relative bandwidth (0 = narrow, 1 = full span)

• id 2: stochastic grain-skip

  • behaviour

    • chops the signal into short grains and mutes some randomly, creating gritty drop-outs

  • notes

    • grain length and muting probability are continuous

  • parameters

    • a = skip probability per grain (0 = never skip, 1 = skip all)

    • b = grain length fraction of note (0 = very short, 1 = long grain)

• id 0: constant

  • behaviour

    • effect intensity remains fixed throughout the note

  • parameters

    • a = fixed intensity (0 = bypass, 1 = full effect)
    • b = onset delay fraction (0 = start immediately, 1 = start at end)

• id 1: ramp in-out

  • behaviour

    • intensity rises, holds, then falls in a triangular envelope

  • parameters

    • a = rise duration fraction (0 = instant, 1 = entire note)
    • b = fall duration fraction (same mapping)

• id 2: periodic window

  • behaviour

    • toggles effect on/off in a repeating window pattern

  • parameters

    • a = period fraction of note (0 = very fast, 1 = one cycle)
    • b = duty cycle (0 = always off, 1 = always on)

• id 3: random burst

  • behaviour

    • launches bursts of effect following a poisson process

  • parameters

    • a = expected bursts per note (0 = none, 1 = ~20 bursts)

    • b = burst duration fraction (0 = very short, 1 = half the note)

• effects a, b control what* the effect does (depth, rate, centre, probability, grain length)
• progressions a, b control how* it changes over time (intensity, timing, period, duty, bursts)

• completeness

  • cover smooth morphing, rhythmic gating, and stochastic variation

• continuity

  • all mappings are continuous, avoiding clicks or sudden jumps

• interoperability

  • can be combined with amplitude, frequency, envelope, decorators for rich textures

• musical relevance

  • slow morphs for pads, gated filters for rhythmic patterns, grain-skip for glitch effects

• global lfo vibrato or tremolo (handled by decorator dimension)
• multiband or evolving filter shapes beyond single band-pass
• note-to-note modulation (handled by per-voice or performance controllers)
• dynamic spectral resynthesis (requires additive-plus-filter or convolution)

the dynamics domain adds a fourth axis of in-note variation, giving designers the tools to inject motion, rhythm, and randomness into their sounds. with its families of effects and progressions, it remains fully continuous, parameter-pure, and additive-only, fitting seamlessly into the super-instrument's architecture.