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renato97 014e636889 feat: professional reggaeton production engine — 7 SDD changes, 302 tests

- section-energy: track activity matrix + volume/velocity multipliers per section
- smart-chords: ChordEngine with voice leading, inversions, 4 emotion modes
- hook-melody: melody engine with hook/stabs/smooth styles, call-and-response
- mix-calibration: Calibrator module (LUFS volumes, HPF/LPF, stereo, sends, master)
- transitions-fx: FX track with risers/impacts/sweeps at section boundaries
- sidechain: MIDI CC11 bass ducking on kick hits via DrumLoopAnalyzer
- presets-pack: role-aware plugin presets (Serum/Decapitator/Omnisphere per role)

Full SDD pipeline (propose→spec→design→tasks→apply→verify) for all 7 changes.
302/302 tests passing.

2026-05-03 23:54:29 -03:00

4.8 KiB

Raw Blame History

Proposal: Section Energy Curve

Intent

All 9 arrangement sections sound identical — full-band at static volume. Professional reggaeton builds energy across sections via sparse-to-dense track layering, velocity variation, and section-level volume riding. This change adds the missing dynamics.

Scope

In Scope

Centralized TRACK_ACTIVITY dict: which track roles play in which sections
build_section_structure() sets velocity_mult and vol_mult per section type
Unified _section_active() helper — single source of truth for section activity
All 7 track builders refactored to check centralized activity + apply velocity_mult
RPPBuilder extended to apply per-clip vol_mult (audio items get D_VOL, MIDI items get velocity scaling)
Rename build section to pre-chorus (professional reggaeton convention)
Update integration tests to match new section behavior

Out of Scope

Volume automation envelopes (REAPER VOLENV2) — deferred
Transition FX generation (risers, impacts, filtered sweeps)
Per-section filter automation (AutoFilter cutoff sweeps)
Section scene names in REAPER project — still flat arrangement

Capabilities

Modified Capabilities

section-structure: SectionDef velocity_mult and vol_mult now populated per section type instead of defaulting to 1.0
track-generation: All builders consume centralized activity matrix + section multipliers instead of ad-hoc section name checks

New Capabilities

section-activity: Centralized activity matrix defining which track roles are active per section type
clip-volume: ClipDef receives optional vol_mult field; RPPBuilder applies it to item D_VOL (audio) or velocity scaling (MIDI)

Approach

Principle: Schema fields (velocity_mult, vol_mult) already exist in SectionDef. The bug is they're never populated or consumed. Add the wiring.

Activity matrix — TRACK_ACTIVITY dict in compose.py maps section_type → {role: bool}. Section types: intro, verse, pre-chorus, chorus, bridge, final, outro.
Section multipliers — build_section_structure() sets velocity_mult (controls note velocity) and vol_mult (controls clip gain) based on section type:

Section velocity_mult vol_mult

intro 0.6 0.70

verse 0.7 0.85

pre-chorus 0.85 0.95

chorus 1.0 1.00

bridge 0.6 0.75

final 1.0 1.00

outro 0.4 0.60
Builder refactor — Replace ad-hoc if section.name in ("chorus","final") with _section_active(section, role, activity) check. Multiply MIDI velocities by section.velocity_mult.
RPPBuilder — _build_item() adds D_VOL for audio clips when clip.vol_mult != 1.0. MIDI clips already get velocity-scaled notes from step 3.
Section rename — build → pre-chorus in SECTIONS and all references (DRUMLOOP_ASSIGNMENTS, builder filters). Existing section name "build" only appears in compose.py SECTIONS — no external consumers.

Section	velocity_mult	vol_mult
intro	0.6	0.70
verse	0.7	0.85
pre-chorus	0.85	0.95
chorus	1.0	1.00
bridge	0.6	0.75
final	1.0	1.00
outro	0.4	0.60

Affected Areas

Area	Impact	Description
`scripts/compose.py`	Modified	Add `TRACK_ACTIVITY`, `_section_active()`, update `build_section_structure()`, refactor all 7 builders, rename build→pre-chorus
`src/core/schema.py`	Modified	Add `vol_mult` field to `ClipDef` (optional, default 1.0)
`src/reaper_builder/__init__.py`	Modified	`_build_item()` applies `D_VOL` from `clip.vol_mult`
`tests/test_compose_integration.py`	Modified	Update section name references (build→pre-chorus), add activity matrix tests
`tests/test_section_builder.py`	Modified	Add `velocity_mult`/`vol_mult` population tests

Risks

Risk	Likelihood	Mitigation
RPP `D_VOL` not recognized by REAPER	Low	REAPER .rpp spec documents D_VOL on ITEM; test with actual REAPER load
Section rename breaks test fixtures	Med	Grep all `.py` for "build" section name; CI catches breakage
Activity matrix too strict — creative users want full band in bridge	Low	Activity matrix is a constant at file top — easy to edit; could be CLI flag later

Rollback Plan

Revert commit. No schema migrations needed — vol_mult on ClipDef defaults to 1.0 (zero behavioral change if not set). Section rename is cosmetic in output RPP.

Dependencies

None — no new packages, no external APIs.

Success Criteria

All sections sound audibly different (sparse intro → dense chorus)
Drums + pad only in intro (no bass, no lead, no chords)
Full band in chorus (all 7 tracks active)
Velocity differences between verse (soft) and chorus (hard)
110 existing tests still pass
.rpp output opens in REAPER without errors

4.8 KiB Raw Blame History