amcs-producer-notes-generator

name	amcs-producer-notes-generator
description	Generate production notes defining song structure, hooks, instrumentation hints, per-section tags, and mix parameters. Aligns with style spec and blueprint production guidelines. Use when creating arrangement, dynamics, and audio engineering guidance for composition and rendering.

AMCS Producer Notes Generator

Creates comprehensive production notes that define arrangement structure, hook placement, instrumentation details, per-section dynamics, and mix parameters aligned with style specifications.

When to Use

Invoke this skill after PLAN and STYLE generation to create production notes. Runs in parallel with LYRICS node and feeds into COMPOSE.

Input Contract

inputs:
  - name: sds_producer
    type: amcs://schemas/producer-notes-1.0.json
    required: true
    description: Producer notes entity from SDS with user preferences
  - name: plan
    type: amcs://schemas/plan-1.0.json
    required: true
    description: Section order and duration targets
  - name: style
    type: amcs://schemas/style-1.0.json
    required: true
    description: Musical style for alignment
  - name: seed
    type: integer
    required: true
    description: Determinism seed (use seed+3 for this node)

Output Contract

outputs:
  - name: producer_notes
    type: amcs://schemas/producer-notes-1.0.json
    description: |
      Complete production spec with:
      - structure: Section arrangement string
      - hooks: Hook count and placement
      - instrumentation: Additional instrument notes
      - section_meta: Per-section tags and durations
      - mix: LUFS, space, stereo width parameters

Determinism Requirements

• Seed: run_seed + 3 for any stochastic section tag selection
• Temperature: 0.2 if LLM used for production recommendations
• Top-p: 0.8
• Retrieval: None (blueprint and style are local)
• Hashing: Hash final producer_notes JSON for provenance

Constraints & Policies

• Structure MUST match plan.section_order
• Per-section target_duration_sec MUST sum to within ±30s of sds.constraints.duration_sec
• Section names in section_meta MUST exist in structure
• Hook count (hooks) MUST be ≥1 for genres requiring memorable elements
• Instrumentation MUST NOT conflict with style instrumentation
• Per-section tags MUST NOT conflict with global style tags
• If hooks = 0, log warning about memorability risk

Implementation Guidance

Step 1: Build Structure String

1. Extract plan.section_order
2. Format as hyphen-separated string: "Intro–Verse–PreChorus–Chorus–..."
3. Store in producer_notes.structure
4. Validate all sections from plan are included

Step 2: Determine Hook Count and Placement

1. Read sds_producer.hooks as base count
2. If plan.evaluation_targets.hook_density exists:
   • Calculate recommended hooks: num_chorus_sections * 1.5
   • Use max(sds_hooks, recommended_hooks)
3. If hooks < 1 and genre requires hooks (Pop, Hip-Hop), log warning
4. Store final count in producer_notes.hooks

Step 3: Expand Instrumentation

1. Copy style.instrumentation as base
2. Add sds_producer.instrumentation if provided
3. Remove duplicates
4. For each section in plan.section_order:
   • Determine section-specific instruments from blueprint production guidelines
   • Example: "Bridge" often features minimal instrumentation
   • Add to section_meta[section].tags as instrument tags

Step 4: Generate Per-Section Metadata

For each section in structure:

1. Determine Tags:

   • Load blueprint production guidelines for section type
   • Example guidelines:
     • Intro: ["instrumental", "low energy", "atmospheric"]
     • Verse: ["storytelling", "moderate energy"]
     • PreChorus: ["build-up", "rising energy", "add percussion"]
     • Chorus: ["anthemic", "full instrumentation", "hook-forward"]
     • Bridge: ["minimal", "dramatic shift", "breakdown"]
     • Outro: ["fade-out", "reflective"]
   • Merge with sds_producer.section_meta[section].tags if provided
   • Validate no conflicts with global style tags

2. Set Duration:

   • Use sds_producer.section_meta[section].target_duration_sec if provided
   • Otherwise calculate proportionally from sds.constraints.duration_sec
   • Store in section_meta[section].target_duration_sec

3. Store Section Metadata:

   {
     "section_meta": {
       "Intro": {
         "tags": ["instrumental", "low energy"],
         "target_duration_sec": 10
       },
       "Chorus": {
         "tags": ["anthemic", "hook-forward", "full instrumentation"],
         "target_duration_sec": 25
       }
     }
   }
   

Step 5: Define Mix Parameters

1. LUFS Target:

   • Default: -12.0 LUFS (modern streaming standard)
   • Adjust for genre:
     • Electronic/Hip-Hop: -9.0 to -11.0 (louder)
     • Jazz/Classical: -14.0 to -16.0 (more dynamic range)
   • Use sds_producer.mix.lufs if provided

2. Space/Reverb:

   • Map from style mood:
     • "intimate" → "dry"
     • "epic" → "lush"
     • "vintage" → "vintage tape"
   • Use sds_producer.mix.space if provided

3. Stereo Width:

   • Default: "normal"
   • "anthemic" energy → "wide"
   • "intimate" mood → "narrow"
   • Use sds_producer.mix.stereo_width if provided

4. Store in producer_notes.mix

Step 6: Validate and Return

1. Validate structure matches plan section order
2. Check section duration sum: abs(sum - duration_sec) ≤ 30
3. Ensure all section_meta keys exist in structure
4. Validate against amcs://schemas/producer-notes-1.0.json
5. Compute SHA-256 hash
6. Return producer_notes with hash metadata

Examples

Example 1: Christmas Pop Production

Input:

{
  "sds_producer": {
    "structure": "",
    "hooks": 2,
    "instrumentation": ["sleigh bells"],
    "section_meta": {
      "Chorus": {"tags": ["crowd-chant"]}
    },
    "mix": {"lufs": -12.0, "space": "lush"}
  },
  "plan": {
    "section_order": ["Intro", "Verse", "PreChorus", "Chorus", "Bridge", "Chorus"]
  },
  "style": {
    "energy": "anthemic",
    "instrumentation": ["brass", "upright bass", "handclaps"],
    "mood": ["upbeat", "cheeky"]
  },
  "seed": 45
}

Output:

{
  "structure": "Intro–Verse–PreChorus–Chorus–Bridge–Chorus",
  "hooks": 2,
  "instrumentation": ["brass", "upright bass", "handclaps", "sleigh bells"],
  "section_meta": {
    "Intro": {
      "tags": ["instrumental", "low energy", "sleigh bells"],
      "target_duration_sec": 10
    },
    "Verse": {
      "tags": ["storytelling", "moderate energy"],
      "target_duration_sec": 30
    },
    "PreChorus": {
      "tags": ["build-up", "handclaps", "rising energy"],
      "target_duration_sec": 15
    },
    "Chorus": {
      "tags": ["anthemic", "hook-forward", "full instrumentation", "crowd-chant"],
      "target_duration_sec": 25
    },
    "Bridge": {
      "tags": ["minimal", "dramatic shift", "brass feature"],
      "target_duration_sec": 20
    }
  },
  "mix": {
    "lufs": -12.0,
    "space": "lush",
    "stereo_width": "wide"
  },
  "_hash": "jkl012...",
  "_total_duration": 175
}

Common Pitfalls

1. Structure Mismatch: Not matching plan section order breaks composition
2. Duration Overflow: Section durations summing >30s beyond target causes rendering issues
3. Missing Sections: Not including section_meta for all sections in structure
4. Tag Conflicts: Per-section tags conflicting with global style tags
5. Zero Hooks: Setting hooks=0 for hook-dependent genres fails validation
6. Invalid LUFS: Using LUFS values outside reasonable range (-20 to -6)
7. Instrumentation Duplication: Not deduplicating combined instrument lists