loudness

• 0 absolute envelope

  • description: master loudness contour over time
  • real-world analogy: fade-ins, long crescendos, global swells
  • notes: defines a ceiling; all events are scaled proportionally to fit

• 1 per-voice envelope

  • description: loudness shaping per voice over time
  • real-world analogy: lead/support balance, instrument emphasis
  • notes: defines a weight profile for each voice across the timeline

• 2 region emphasis

  • description: time-local loudness emphasis based on structural divisions
  • real-world analogy: chorus/verse contrast, form-driven dynamics
  • notes: used in tandem with segmentation and/or hierarchy

• 0 absolute envelope

  • a: curvature of rise/fall (0 = linear, 1 = slow-attack sharp-release)
  • b: peak time (0 = early, 1 = late)

• 1 per-voice envelope

  • a: contrast between lead and background voices
  • b: voice-role skew over time (0 = fixed, 1 = rotating)

• 2 region emphasis

  • a: inter-region loudness contrast
  • b: transition smoothness between regions all parameters are in [0, 1].

the forms are multiplicative and together produce the final per-event amplitude scaler:

loudness(t, v) =
    absolute_envelope(t) *
    per_voice_weight(t, v) *
    region_emphasis(t)

each factor is precomputed, bounded in [0, 1], and strictly static - ensuring deterministic loudness for all events at all times. flat settings disable the corresponding effect (e.g. all-ones absolute_envelope gives full dynamic headroom).

• absolute enables timeline-wide energy control
• per-voice balances instruments or layers over time
• region allows macrostructure shaping through contrast and phrasing these map directly to musical concepts (crescendo, voice lead, chorus lift) and align with a fully precomputed additive engine.

• runtime dynamics (compression, ducking, sidechain)
• perceptual normalization or loudness metering
• adaptive gain compensation or feedback-driven adjustment such features would introduce non-determinism and are intentionally excluded. for expressive shifts, modulation or mutation domains can introduce controlled variation upstream.

the loudness domain provides compact, composable control over the perceived amplitude of sound events, while respecting a strict upper bound. it supports:

• global dynamics
• inter-voice balance
• structure-aligned phrasing and integrates transparently with envelope and spectral shaping domains. by ensuring no overlapping events exceed the available dynamic budget, it preserves clarity, precision, and headroom at all scales.