# Phase 3: Artist Data Structure - Research

**Researched:** 2026-04-10
**Domain:** Artist folder structure generation, song structure templates by genre with Suno metatag placement
**Confidence:** HIGH

## Summary

Phase 3 has two plans: (03-01) artist folder structure generation and (03-02) song structure template library by genre. The critical finding is that Plan 03-01 is largely already implemented -- the create-artist wizard's Step 06 (`06-review-validate.md`) already writes `bible.md`, `discography.md`, and creates `tracks/` for each artist. What remains for 03-01 is verification that the wizard output matches ART-03 requirements, and potentially updating `STRUCTURE.md` and `artists/README.md` to reflect the completed state.

Plan 03-02 is the substantive new work. ART-04 requires "pre-built song structure templates by genre (pop ABABCB, rap AABA, ballad ABACDC, etc.) stored as reusable references." These templates must live in `reference/templates/`, covering at least 5 genres (pop, rap, ballad, rock, electronic per the success criteria). Each template needs section ordering with Suno metatags and guidance on delivery tags, line counts, and structural conventions for that genre. These templates will be consumed by Phase 4's track creation workflow.

The song structure research is well-grounded in standard musicology (ABABCB verse-chorus, AABA 32-bar, etc.) and verified against Suno's metatag system documented in `reference/suno/format.md`. The project already has the complete Suno metatag vocabulary -- the templates just need to arrange those metatags into genre-appropriate structures.

**Primary recommendation:** Create one markdown template file per genre in `reference/templates/songs/` (subdirectory to keep song templates separate from artist templates). Each template specifies section order, Suno metatags, recommended vocal delivery tags, line count guidance per section, and notes on genre conventions. Verify Plan 03-01 by running the wizard and confirming folder structure output.

## Standard Stack

This phase produces no code -- only markdown reference files (song structure templates) and minor updates to existing files.

### Core

| Component | Location | Purpose | Why Standard |
|-----------|----------|---------|--------------|
| Song structure templates | `reference/templates/songs/*.md` | Genre-specific section ordering and metatag placement | Reusable references for Phase 4 track creation workflow |
| Artist folder structure | `artists/[name]/` | Per-artist dedicated folder | Already implemented by wizard Step 06 |

### Supporting

| Component | Location | Purpose | When to Use |
|-----------|----------|---------|-------------|
| Suno format reference | `reference/suno/format.md` (existing) | Metatag vocabulary, structure tags, delivery tags | Song templates reference these tags |
| Glossary | `reference/glossary.md` (existing) | Canonical section terminology (Verse, Chorus, Bridge, etc.) | Song templates use English canonical terms |
| Bible template | `reference/templates/bible-template.md` (existing) | Artist bible schema | Already complete from Phase 2 |
| Discography template | `reference/templates/discography-template.md` (existing) | Empty discography stub | Already complete from Phase 2 |

### Alternatives Considered

| Instead of | Could Use | Tradeoff |
|------------|-----------|----------|
| One file per genre in `songs/` subdirectory | All song structures in a single file | Single file would be 300+ lines and unwieldy. Separate files allow browsing by genre (success criteria #3: "user can browse to see available song structures"). |
| `reference/templates/songs/` subdirectory | Flat in `reference/templates/` | Flat mixing of bible/discography templates with 5+ song structure files creates clutter. Subdirectory keeps concerns separated. |
| Prescriptive section-by-section templates | Generic structure descriptions | Generic descriptions ("this genre uses verse-chorus form") are not actionable. Templates with exact metatag placement are copy-paste ready for Phase 4. |

## Architecture Patterns

### Recommended Template Directory Structure

```
reference/templates/
+-- bible-template.md           # (existing) Artist bible schema
+-- discography-template.md     # (existing) Empty discography stub
+-- songs/
    +-- README.md               # Index of available song structures
    +-- pop.md                  # Pop (ABABCB)
    +-- rap.md                  # Rap/Hip-Hop (Verse-Hook)
    +-- ballad.md               # Ballad (ABACDC / verse-driven)
    +-- rock.md                 # Rock (ABABCB + Solo)
    +-- electronic.md           # Electronic/EDM (Build-Drop)
```

### Pattern 1: Song Structure Template Format

**What:** Each song structure template defines the genre's standard section ordering using Suno metatags, with guidance on line counts, delivery tags, and structural conventions.

**When to use:** Phase 4 track creation workflow will read the relevant genre template to structure lyrics correctly.

**Template format:**

```markdown
---
last-updated: 2026-04-10
genre: [Genre Name]
aliases: [Alternative names for this genre family]
bpm-range: [BPM range from reference/suno/format.md]
---

# [Genre] - Song Structure Template

## Standard Structure

[Letter notation: e.g., ABABCB]

## Section Flow

### 1. [Intro]
- **Suno metatag:** `[Intro]`
- **Typical content:** [Instrumental / short vocal hook / atmosphere-setting]
- **Lines:** [0-2 lyric lines, or instrumental]
- **Delivery tag:** [if applicable]

### 2. [Verse 1]
- **Suno metatag:** `[Verse 1]`
- **Role:** [Narrative function in this genre]
- **Lines:** [recommended line count]
- **Delivery tag:** [genre-typical delivery]

[...remaining sections...]

## Variations

[Common variations of the standard structure for this genre]

## Notes

[Genre-specific guidance: tempo, energy arc, Suno tips]
```

### Pattern 2: Artist Folder Structure (Already Implemented)

**What:** Each artist gets `artists/[name-in-kebab-case]/` with `bible.md`, `discography.md`, and `tracks/` subdirectory.

**Current state:** The wizard's Step 06 (`06-review-validate.md`) already creates this structure. The "Ecriture des Fichiers" section specifies:
1. Artist folder: `artists/[name-in-kebab-case]/`
2. Bible: `artists/[name]/bible.md`
3. Discography: `artists/[name]/discography.md`
4. Tracks directory: `artists/[name]/tracks/`

**What Plan 03-01 actually needs to do:** Verify the wizard produces this correctly. No new code or templates needed for the folder structure itself.

### Anti-Patterns to Avoid

- **Over-prescriptive templates:** Song structure templates should be guides, not straitjackets. Each template should include a "Variations" section showing common alternatives. Claude should use the template as a starting point, not a rigid formula.

- **Duplicating Suno metatag documentation:** The templates reference metatags but should not re-document what each metatag does. That is `reference/suno/format.md`'s job. Templates say "use `[Bridge]` here" -- format.md explains what `[Bridge]` does.

- **Genre-mixing in a single template:** Each template covers one genre family. Cross-genre tracks (e.g., pop-rock) use the primary genre's template and borrow elements from the secondary. Do not create hybrid templates.

## Don't Hand-Roll

| Problem | Don't Build | Use Instead | Why |
|---------|-------------|-------------|-----|
| Metatag vocabulary | Custom section tag lists in templates | `reference/suno/format.md` section tags table | Already comprehensive, maintained separately |
| Delivery tag options | Genre-specific delivery lists | `reference/suno/format.md` delivery categories | 8 categories with full tag inventory already exist |
| BPM ranges by genre | Custom tempo tables | `reference/suno/format.md` "Ranges par Genre" | Already has BPM ranges for 9 genre families |
| Section terminology | French translations of section names | `reference/glossary.md` | English terms are canonical per project convention |

**Key insight:** The metatag and tag vocabulary already exists in `format.md`. Song structure templates arrange this vocabulary into genre-appropriate sequences -- they are structural recipes, not knowledge containers.

## Common Pitfalls

### Pitfall 1: Templates Too Rigid for Creative Variation

**What goes wrong:** Templates define a single structure with no alternatives. Claude follows the template rigidly, producing formulaic tracks that all sound structurally identical within a genre.

**Why it happens:** Templates designed as rules rather than guides.

**How to avoid:** Each template includes a "Variations" section with 2-3 common alternative structures. The Phase 4 track workflow should use the standard structure by default but allow the user (or Claude, based on the track's concept) to select a variation. Example: pop template has ABABCB as standard but AABABCB (double verse intro) and ABABCBB (double chorus ending) as variations.

**Warning signs:** All tracks for a genre having identical section counts and ordering.

### Pitfall 2: Line Count Guidance Too Precise

**What goes wrong:** Templates specify exact line counts ("Verse must be 8 lines"). Claude treats this as a hard constraint. Some track concepts need shorter or longer verses.

**Why it happens:** Confusing guidance with constraint.

**How to avoid:** Use ranges ("4-8 lines") and qualify as "typical" not "required." The real constraint is Suno's 5000 character limit for lyrics, not a per-section line count. The template provides typical proportions; the track workflow enforces Suno limits.

**Warning signs:** Track lyrics being padded or truncated to hit exact line counts.

### Pitfall 3: Ignoring the Build-Drop Pattern for Electronic

**What goes wrong:** Electronic music template uses a verse-chorus structure. EDM tracks come out sounding like pop tracks with synthesizers.

**Why it happens:** Applying verse-chorus form universally.

**How to avoid:** The electronic template must use the Build-Drop structure (Intro -> Build -> Drop -> Breakdown -> Build -> Drop -> Outro) which is the standard EDM form. Suno supports `[Build]`, `[Drop]`, `[Breakdown]` metatags specifically for this. The electronic template is structurally different from pop/rock/rap/ballad templates.

**Warning signs:** Electronic tracks with traditional verse-chorus sections instead of build-drop energy arcs.

### Pitfall 4: Plan 03-01 Duplicating Work Already Done

**What goes wrong:** Plan 03-01 re-implements folder creation logic that already exists in the wizard Step 06.

**Why it happens:** Not recognizing that Phase 2 already delivers ART-03.

**How to avoid:** Plan 03-01 should VERIFY the wizard output, not rebuild it. The folder structure generation is already specified in `06-review-validate.md` lines 99-131. Plan 03-01's scope is: (a) run the wizard to confirm it creates the correct structure, (b) update any documentation that references Phase 3 as the source of folder structure (it is now Phase 2), (c) ensure `STRUCTURE.md` accurately reflects the current state.

**Warning signs:** Creating redundant folder creation logic in a new location.

### Pitfall 5: Missing README Index for Song Templates

**What goes wrong:** Song templates exist in `reference/templates/songs/` but there is no index. Users cannot easily browse available structures (success criteria #3).

**Why it happens:** Templates created without considering discoverability.

**How to avoid:** Create a `reference/templates/songs/README.md` that lists all available song structures with one-line descriptions, genre aliases, and links. This satisfies "user can browse `reference/templates/` to see available song structures before creating a track."

**Warning signs:** User asking "what structures are available?" and Claude having to list files manually.

## Code Examples

These are markdown reference file examples -- the system is zero-code.

### Song Structure Template: Pop (ABABCB)

```markdown
---
last-updated: 2026-04-10
genre: Pop
aliases: [Synth-Pop, Electro-Pop, Indie Pop, Art Pop, Dark Pop, Bedroom Pop]
bpm-range: 100-130 BPM
---

# Pop - Song Structure Template

## Standard Structure

**ABABCB** -- Verse / Chorus / Verse / Chorus / Bridge / Chorus

## Section Flow

### 1. [Intro]
- **Suno metatag:** `[Intro]`
- **Content:** Instrumental or short vocal hook (1-2 lines max)
- **Lines:** 0-2
- **Notes:** Sets atmosphere. Can be `[Instrumental]` or a melodic hook.

### 2. [Verse 1]
- **Suno metatag:** `[Verse 1]`
- **Role:** Establishes the narrative, introduces the track's world
- **Lines:** 4-8
- **Delivery:** Genre-typical, match artist's vocal style

### 3. [Pre-Chorus]
- **Suno metatag:** `[Pre-Chorus]`
- **Role:** Builds tension, transitions from verse energy to chorus energy
- **Lines:** 2-4
- **Notes:** Optional but common in pop. Melodically ascends toward the chorus.

### 4. [Chorus]
- **Suno metatag:** `[Chorus]`
- **Role:** Emotional peak, hook, most memorable part
- **Lines:** 4-6
- **Delivery:** Typically more powerful than verses
- **Notes:** Same lyrics each repetition to encourage Suno melodic consistency.

### 5. [Verse 2]
- **Suno metatag:** `[Verse 2]`
- **Role:** Advances the narrative, new angle on the theme
- **Lines:** 4-8
- **Notes:** Must NOT repeat Verse 1 content (CLAUDE.md rule #7)

### 6. [Pre-Chorus]
- **Suno metatag:** `[Pre-Chorus]`
- **Lines:** 2-4
- **Notes:** Can be identical to first pre-chorus or slightly varied

### 7. [Chorus]
- **Suno metatag:** `[Chorus]`
- **Lines:** 4-6

### 8. [Bridge]
- **Suno metatag:** `[Bridge]`
- **Role:** Contrasting section -- new harmonic, rhythmic, or emotional territory
- **Lines:** 2-4
- **Delivery:** Often a shift (e.g., stripped-back, or key change)

### 9. [Chorus]
- **Suno metatag:** `[Chorus]`
- **Lines:** 4-6
- **Notes:** Final chorus. Can use `[Final Chorus | key change]` for modulation.

### 10. [Outro]
- **Suno metatag:** `[Outro]`
- **Content:** Fade, instrumental resolution, or final hook repetition
- **Lines:** 0-2
- **Notes:** Optional. Can use `[Fade Out]` or `[End]`.

## Variations

| Variation | Structure | When to Use |
|-----------|-----------|-------------|
| Double verse intro | AABABCB | Story-driven tracks that need more narrative setup |
| Post-chorus | AB(post)AB(post)CB | Tracks with a secondary hook after the chorus |
| No bridge | ABAB(Outro) | Simple, hook-driven tracks |
| Double chorus ending | ABABCBB | Emotional climax, anthem-style ending |

## Notes

- Pop tracks typically run 2:30-3:30 in Suno (target ~2000-2500 chars lyrics)
- The chorus is king -- keep it concise (4-6 lines), melodically strong
- Pre-chorus is optional but adds polish; omit for stripped-back pop
- Suno tip: Using identical `[Chorus]` tags (not `[Chorus 1]`, `[Chorus 2]`) encourages melodic repetition between choruses
```

### Song Structure Template: Electronic/EDM (Build-Drop)

```markdown
---
last-updated: 2026-04-10
genre: Electronic
aliases: [EDM, House, Deep House, Tech House, Techno, Trance, Future Bass, Synthwave]
bpm-range: 120-150 BPM (varies by subgenre)
---

# Electronic - Song Structure Template

## Standard Structure

**Build-Drop** -- Intro / Build / Drop / Breakdown / Build / Drop / Outro

This is NOT a verse-chorus structure. Electronic music uses energy arcs, not narrative arcs.

## Section Flow

### 1. [Intro]
- **Suno metatag:** `[Intro]`
- **Content:** Atmospheric, rhythmic foundation. Often drums-only or pads.
- **Lines:** 0 (instrumental) or 1-2 vocal lines
- **Notes:** Sets BPM and energy floor. Can use `[Instrumental]`.

### 2. [Verse 1]
- **Suno metatag:** `[Verse 1]`
- **Role:** Vocal layer over the groove, if vocals present
- **Lines:** 2-4 (sparse -- electronic vocals are minimal)
- **Delivery:** Often `[Soft]`, `[Breathy]`, or `[Filtered Vocals]`
- **Notes:** Many EDM tracks have no traditional verses. Skip if purely instrumental.

### 3. [Build]
- **Suno metatag:** `[Build]` or `[Build-Up]`
- **Role:** Rising intensity leading to drop. Tension-building.
- **Lines:** 0-2 (often a repeated phrase or vocal chop)
- **Notes:** This is the "pre-chorus equivalent" in EDM. Energy rises.

### 4. [Drop]
- **Suno metatag:** `[Drop]`
- **Role:** Peak energy release. The climax.
- **Lines:** 0-2 (hook phrase, or `[Instrumental]`)
- **Delivery:** `[Powerful]`, `[Intense]`
- **Notes:** The defining moment. Bass-heavy, rhythmically intense.

### 5. [Breakdown]
- **Suno metatag:** `[Breakdown]` or `[Break]`
- **Role:** Energy drop. Stripped arrangement, atmospheric.
- **Lines:** 0-2
- **Notes:** Contrast with the drop. Often pads-only or minimal percussion.

### 6. [Build]
- **Suno metatag:** `[Build]`
- **Lines:** 0-2
- **Notes:** Second build, leading to the second drop.

### 7. [Drop]
- **Suno metatag:** `[Drop]`
- **Lines:** 0-2
- **Notes:** Second drop. Often more intense than the first.

### 8. [Outro]
- **Suno metatag:** `[Outro]`
- **Content:** Energy wind-down. Return to intro elements.
- **Lines:** 0-1
- **Notes:** `[Fade Out]` or gradual element removal.

## Variations

| Variation | Structure | When to Use |
|-----------|-----------|-------------|
| Vocal EDM | Intro / Verse / Build / Drop / Verse / Build / Drop / Outro | Tracks with strong vocal presence (vocal trance, future bass) |
| Extended breakdown | Intro / Build / Drop / Long Breakdown with Verse / Build / Drop / Outro | Deep house, progressive house |
| Triple drop | Intro / Build / Drop / Breakdown / Build / Drop / Breakdown / Build / Drop / Outro | Festival-style EDM, longer tracks |

## Notes

- Electronic tracks benefit from Suno's `[no vocals]` metatag for instrumental sections
- Use `[Instrumental]` liberally -- EDM breathes through instrumental space
- Subgenre BPM matters: House 120-130, Techno 125-150, Trance 130-145, DnB 160-180
- The drop is the chorus equivalent -- it should be the most memorable moment
- Suno handles `[Build]` and `[Drop]` well in V5.5
```

### Song Structure Template: Rap (Verse-Hook)

```markdown
---
last-updated: 2026-04-10
genre: Rap / Hip-Hop
aliases: [Trap, Boom Bap, Drill, Grime, Cloud Rap, Lo-Fi Hip-Hop]
bpm-range: 130-170 BPM (half-time feel)
---

# Rap / Hip-Hop - Song Structure Template

## Standard Structure

**AABA** -- Verse / Hook / Verse / Hook / Verse / Hook (3 verses, 3 hooks)

## Section Flow

### 1. [Intro]
- **Suno metatag:** `[Intro]`
- **Content:** Beat drop-in, ad-libs, or short spoken intro
- **Lines:** 0-4
- **Delivery:** `[Spoken]` or `[Rapped]`
- **Notes:** Sets the tone. Can be instrumental or a producer tag.

### 2. [Verse 1]
- **Suno metatag:** `[Verse 1]`
- **Role:** Main narrative content, establishes the topic/story
- **Lines:** 8-16 (16 bars standard in boom bap; 8-12 in trap/drill)
- **Delivery:** `[Rapped]`, `[Trap Flow]`, `[Boom Bap Flow]`, or `[Melodic Rap]`
- **Notes:** Dense lyrical content. Rhyme scheme varies by subgenre.

### 3. [Chorus]
- **Suno metatag:** `[Chorus]` or `[Hook]`
- **Role:** Catchy, memorable hook. Sums up the track's message.
- **Lines:** 4-8
- **Delivery:** Often more melodic than verses. `[Melodic Rap]` or `[Sung]`
- **Notes:** In rap, "hook" and "chorus" are interchangeable. Use `[Chorus]` for Suno consistency.

### 4. [Verse 2]
- **Suno metatag:** `[Verse 2]`
- **Role:** Deepens the narrative, new angle or escalation
- **Lines:** 8-16
- **Notes:** Must NOT repeat Verse 1 content (CLAUDE.md rule #7)

### 5. [Chorus]
- **Suno metatag:** `[Chorus]`
- **Lines:** 4-8

### 6. [Verse 3]
- **Suno metatag:** `[Verse 3]`
- **Role:** Conclusion, twist, or climax of the narrative
- **Lines:** 8-16
- **Notes:** Optional in shorter tracks. Common in boom bap, less common in trap.

### 7. [Chorus]
- **Suno metatag:** `[Chorus]`
- **Lines:** 4-8

### 8. [Outro]
- **Suno metatag:** `[Outro]`
- **Content:** Ad-libs, beat fade, or final statement
- **Lines:** 0-4
- **Notes:** Optional. `[Fade Out]` or `[End]`.

## Variations

| Variation | Structure | When to Use |
|-----------|-----------|-------------|
| 2-verse (trap) | Verse / Hook / Verse / Hook / Outro | Trap, drill -- shorter, hook-driven |
| Bridge before final hook | Verse / Hook / Verse / Hook / Bridge / Hook | Emotional rap, storytelling tracks |
| No hook (freestyle) | Verse 1 / Verse 2 / Verse 3 | Pure lyrical showcase, cypher-style |
| Intro hook | Hook / Verse / Hook / Verse / Hook | Hook-first for immediate catchiness |

## Notes

- Rap tracks in Suno: keep lines moderate length (8-12 syllables ideal, avoids slurring at tempo)
- `[Rapped]` delivery tag is critical -- without it, Suno may sing the lyrics
- For trap: `[Trap Flow]`, `[808 Bass]` in style prompt, half-time feel notation
- Bridge is rare in rap but effective for emotional tracks
- Ad-libs (`[Ad-libs]`) can be placed after verse sections for authenticity
```

## State of the Art

| Aspect | Status | Impact |
|--------|--------|--------|
| Artist folder structure | Already implemented in Phase 2 wizard Step 06 | Plan 03-01 is verification, not implementation |
| Bible template | Complete (9 sections, Phase 2) | No changes needed |
| Discography template | Complete (Phase 2) | No changes needed |
| Song structure templates | Not yet created | Plan 03-02 is the substantive new work |
| Suno metatag vocabulary | Complete in `reference/suno/format.md` | Templates arrange existing vocabulary |

**Important observation:** The roadmap says Plan 03-01 is "Artist folder structure generation (integrated into wizard output)." This is already done -- the wizard Step 06 creates `artists/[name]/bible.md`, `artists/[name]/discography.md`, and `artists/[name]/tracks/`. Plan 03-01 should be scoped as a verification + documentation update plan, not an implementation plan.

## Open Questions

1. **Should song templates include example lyrics?**
   - What we know: Templates need to be actionable for Phase 4. Example lyrics would show expected format.
   - What's unclear: Whether example lyrics add value or create noise (templates are structural guides, not creative content).
   - Recommendation: Include 1-2 example lines per section showing format (e.g., line length, metatag placement) but NOT full example lyrics. The bible example (LUNA/NOVA) already exists for creative reference.

2. **Should there be more than 5 genre templates?**
   - What we know: Success criteria require "at least 5 genres (pop, rap, ballad, rock, electronic)." The Suno format reference lists many more genres.
   - What's unclear: Whether additional templates (R&B, country, jazz, etc.) add value now or should be deferred.
   - Recommendation: Start with the 5 required genres. The template format is established; additional genres can be added incrementally. The README index should note this is extensible.

3. **Subdirectory `songs/` vs flat in `templates/`?**
   - What we know: Currently `reference/templates/` has 2 files (bible-template, discography-template). Adding 5+ song templates plus a README would create 8+ files in a flat directory.
   - What's unclear: Whether the project will add more template types later.
   - Recommendation: Use `reference/templates/songs/` subdirectory. Keeps song structure templates separate from artist templates. Update `STRUCTURE.md` to reflect this.

## Sources

### Primary (HIGH confidence)
- `reference/suno/format.md` -- Suno V5.5 metatags, section tags, delivery tags, BPM ranges (project-local, authoritative)
- `reference/glossary.md` -- Canonical section terminology (project-local, authoritative)
- `.claude/skills/create-artist/steps/06-review-validate.md` -- Wizard folder creation logic (project-local)
- `.claude/skills/create-artist/SKILL.md` -- Wizard output specification (project-local)
- `artists/README.md` -- Folder structure conventions (project-local, authoritative)
- `STRUCTURE.md` -- Project hierarchy (project-local)

### Secondary (MEDIUM confidence)
- [MasterClass: Common Song Structures](https://www.masterclass.com/articles/songwriting-101-learn-common-song-structures) -- ABABCB, AABA, AAA forms
- [OMari MC: Complete Guide to Song Form & Structure](https://www.omarimc.com/a-complete-guide-to-song-form-structure-examples-aaba-aaa-abab-abac/) -- Genre-specific structures
- [EDM Tips: EDM Song Structure](https://edmtips.com/edm-song-structure/) -- Build-Drop pattern for electronic
- [Cymatics: EDM Song Structure](https://cymatics.fm/blogs/production/edm-song-structure) -- Intro/Build/Drop/Breakdown form
- [Luke Mounthill: Hip-Hop & Rap Song Structure](https://lukemounthillbeats.com/music-production/hip-hop-rap-song-structure/) -- 16-bar verse, 8-bar hook standard
- [emastered: Rap Song Structure](https://emastered.com/blog/rap-song-structure) -- Verse-Hook-Verse-Hook format
- [HookGenius: Suno Metatags Complete List](https://hookgenius.app/learn/suno-metatags-complete-list/) -- Suno V5+ metatag behavior
- [Neume.io: Song Structure Explained](https://neume.io/blog/song-structure) -- Section functions and roles
- [Sandy Music Lab: Popular Song Structures](https://sandymusiclab.com/examples-of-popular-song-structures/) -- Genre-specific structure examples

### Tertiary (LOW confidence)
- [Suno.wiki: Verse and Chorus](https://wiki.singgenix.com/song-structure.html) -- Notes that Suno AI "tends to have a mind of its own" with structure (caveat for template rigidity)

## Metadata

**Confidence breakdown:**
- Artist folder structure (03-01): HIGH -- Already implemented in Phase 2, just needs verification. Code is in 06-review-validate.md lines 99-131.
- Song structure templates (03-02): HIGH -- Standard musicology structures are well-documented and cross-verified across multiple sources. Suno metatag mapping is verified against project's own format.md.
- Template format design: MEDIUM -- The per-genre file format is a design decision. The recommended format is practical but untested in this project. Phase 4 consumption will validate it.

**Research date:** 2026-04-10
**Valid until:** 2026-05-10 (stable domain -- song structures and Suno metatags are well-established)
