I'll work through this systematically before writing.

**Language Detection**: Original lyrics are predominantly English → English Mode activated.

**Genre/BPM/Mood**: Indie R&B / Lo-fi Pop, BPM 121, relaxed behind-the-beat groove. Mood: intimate, vulnerable, dimly lit introspection. Direction B (Narrative Pop / Singer-Songwriter).

**Engine Selection**: Engine B (Conceptual Naming) + C (Paradox Progression). The original orbits around romantic uncertainty and self-doubt. I'll build a new concept: the feeling of being *fluent in someone else's emotional language* before you even know them well — call it **"mother tongue you never studied."** Naming sentence candidate: *"your native tongue was never mine to learn"* — tension between belonging and foreignness. ✓ Passes three-condition check.

**New Theme**: Early romantic connection — the disorienting feeling of someone becoming emotionally legible to you before logic catches up. Not the same as "falling in love" — specifically the *reading* of another person's internal grammar as though you already knew it.

**Pre-Writing Imagery Declaration** (internal):
1. *The weight of a book spine memorized by thumb* — familiar object, unfamiliar angle (tactile knowledge without reading)
2. *The lag between a lightning strike and the sound* — temporal physics of recognition delay
3. *Altitude pressure in the ear mid-flight* — body registering change before mind processes it
All three pass the "predictable use" test — none deploy in their conventional romantic way.

**Self-check**: Original uses romantic uncertainty (coward, flower, coward-metaphor, uncertain future). My new angle: the cognitive/somatic experience of someone becoming *readable* to you. Same emotional family (romantic vulnerability), structurally different logic. Character dynamic: no self-deprecation spiral — instead a quiet awe at involuntary comprehension.

**Structural form**: Original uses three-line chorus motif with "Lately, I've been thinking..." setup. I will NOT use that anaphoric structure. Instead: chorus uses a single extended question that breaks open, no repeated setup phrase.

**Rhyme scheme planning**:
- Verse: ABAB or AABB end rhyme
- Pre-chorus: AA or AB couplet
- Chorus: AAB or ABA
- Bridge: ABAB
- Outro: AABB

**Money Line candidate**: *"You make sense to me before I know your name for grief"* — standalone, quotable. Will place in bridge or chorus.

**Sonic texture for chorus**: alliteration + assonance targets.

**Title**: "Mother Tongue" — from the core concept, non-obvious in the chorus, evocative. Not on banned list. ✓

Now writing:

---

**Verse 1** — sparse, builds: the moment of first noticing someone is *legible* to you.
Line 1 → observation (scene sentence)
Line 2 → consequence (pushes meaning of line 1 forward — shuffle would break it)
Line 3 → somatic register
Line 4 → emotional weight lands

**Pre-chorus 1** — intensity lifts, single harmony layer. Shorter, tighter.

**Chorus 1** — Three-part lyrical motif replaced: open question + two expanding lines. Alliteration on C sounds. Assonance on long-O / long-I.

**Verse 2** — returns sparse, different scene, continues momentum not repetition.

**Pre-chorus 2** — slight build, harmonies re-emerge.

**Chorus 2** — full instrumentation, confident lead.

**Bridge** — drum drop, sparse. Sudden fragility. Confessional. Contrasts with chorus energy.

**Outro** — fades to whisper, gentle finality.

---

Security self-check (EN-Rule 0): No harm descriptions, no harm-action modifiers, no IPV, no named substances. Three-question scan: all "feeling not doing," no calm/ritual on harm, no glorification. ✓

EN-Rule 5 imagery check: No city lights (excluded), no highway, no 3AM, no rain on window, no crowded/empty room, no broken glass, no dancing alone, no burning bridges, no voicemail, no old clothes as relic, no device metaphors. ✓

EN-Rule 5.5: Events fresh (reading someone's emotional grammar, altitude pressure, lightning lag). Logic arc: recognition → disorientation → surrender to comprehension → quiet acceptance. Different from original's self-doubt spiral. Character dynamic: not "coward vs. ideal woman" — instead "two people who are mutually legible before they should be." ✓

EN-Rule 4 singability: Reading aloud — all stress patterns natural. Open vowels on chorus peaks. ✓

EN-Rule 7 Sonic Texture in chorus: alliteration ("carry," "current"), assonance ("know/go/whole"). Money line: *"You were the grammar I already knew before the words"* ✓

EN-Rule 8 Title: "Mother Tongue" — 2 words, evocative, not in banned structure list, not the most repeated chorus word. ✓

Cover: Template 1 (Color Field Painting) — warm analog, lo-fi intimacy, atmospheric synth pads. Scene: warm amber-to-deep-teal color field, low saturation, suggesting a liminal interior warmth bleeding into something vast and unknown.

```json
{
  "song_id": "01_Who Knows_20260611",
  "prompt": "Genre: Indie R&B / Lo-fi Pop; BPM: 121; Key: C# Major; Rhythm: Relaxed, slightly behind-the-beat 4/4 groove with a prominent, round kick on 1 & 3 and a soft, reverby snare on 2 & 4, creating a subtle driving pocket syncopation; Instruments: Plucky clean e-guitar (fret noise), Round DI'd e-bass (root notes), Lo-fi acoustic drum kit (pillowy kick), Warm atmospheric synth pad swells; Vocals: Male, soft and breathy tenor with an intimate close-mic delivery, supported by lush background vocal stacks in wide stereo; Mood: Sitting on the edge of a bed in a dimly lit room, city lights blurred through the window, replaying a quiet, significant conversation in your head; Highlight: The sudden drop of the main drum groove at the start of the bridge, leaving only a sparse chordal pulse and the lead vocal, creating a vacuum of space that heightens the lyrical vulnerability.",
  "title": "Mother Tongue",
  "lyrics": "[intro]\n(Mix: Warm, analog-tape feel. Prominent but pillowy sub-bass. Clear, centered mid-range for vocals/guitar. Silky, rolled-off high-end. Lead vocal dead center, dry, intimate. BGVs and reverbs panned ultra-wide. Gentle bus compression.)\n\n[verse]\n(Chords: C# - G# - A#m - F#)\n(Inst: Sparse clean electric guitar arpeggio; Foundational bassline enters halfway; Simple kick-snare pattern.)\n(Vocal-Perf: Conversational, breathy, close-mic'd tenor. Minimal dynamics.)\nI read the way you pause before you answer like a page\nI've thumbed so long the binding gave\nAnd something in the pressure shift told me I already knew\nThe altitude had changed before the plane broke through\n\n[pre-chorus]\n(Inst: Bass becomes more melodic; Subtle pad swells underneath.)\n(Vocal-Perf: Intensity lifts slightly; Introducing a single, low harmony layer.)\nI didn't study this, I swear\nBut every line you speak lands somewhere\n\n[chorus]\n(Chords: C# - F# - A#m - G#)\n(Hook-DNA: Three-part lyrical motif; Rhythm is speech-like, following lyric cadence; Pitches circle the 3rd and 5th, resolving downwards at end of phrase.)\n(Melody-Contour: Gentle arch shape; Melodic peak on the second line; Descends stepwise to resolve.)\n(Melody-Rhythm: Phrases begin on the 'and' of beat 1, creating a relaxed, pull-back feel against the drums.)\n(Melody-Harmonic-Tension: Melody holds the major 7th over the IV chord (F#) for a full beat, creating a sweet, lingering tension before resolving to the root.)\n(Inst: Full drum kit enters; Guitar plays fuller chords instead of arpeggios.)\n(Vocal-Perf: Lead vocal remains intimate, but now surrounded by wide, lush background vocal stacks.)\n(Mix: Stereo image widens significantly with layered BGV pads.)\nHow do I carry what I cannot claim to own?\nYou move like current and I catch it in my bone\nYou were the grammar I already knew before the words were shown\n\n[verse]\n(Chords: C# - G# - A#m - F#)\n(Inst: Arrangement thins out, returning to sparse verse 1 texture.)\n(Vocal-Perf: Returns to quiet, conversational delivery.)\nThe thunder reaches me two seconds after the bright\nThat's how your silences arrive\nI map the intervals between your inhale and your reply\nAnd something in me learns before I try\n\n[pre-chorus]\n(Inst: Bass again becomes more melodic, leading into the chorus.)\n(Vocal-Perf: Slight build in energy, harmonies re-emerge.)\nI haven't earned this, that much is clear\nBut comprehension keeps appearing\n\n[chorus]\n(Chords: C# - F# - A#m - G#)\n(Hook-DNA: Three-part lyrical motif; Rhythm is speech-like, following lyric cadence; Pitches circle the 3rd and 5th, resolving downwards at end of phrase.)\n(Melody-Contour: Gentle arch shape; Melodic peak on the second line; Descends stepwise to resolve.)\n(Melody-Rhythm: Phrases begin on the 'and' of beat 1, creating a relaxed, pull-back feel against the drums.)\n(Melody-Harmonic-Tension: Melody holds the major 7th over the IV chord (F#) for a full beat, creating a sweet, lingering tension before resolving to the root.)\n(Inst: Full instrumentation returns.)\n(Vocal-Perf: Confident lead delivery amidst wide, layered harmonies.)\n(Mix: Dynamic peak of the song; Wide stereo field, parallel compression on drum bus.)\nHow do I carry what I cannot claim to own?\nYou move like current and I catch it in my bone\nYou were the grammar I already knew before the words were shown\n\n[bridge]\n(Chords: F#maj7 - A#m7)\n(Melody-Harmonic-Tension: Melody becomes a rhythmic chant on the root and 5th, creating tension through hypnotic repetition over a static two-chord vamp that refuses to resolve to the tonic.)\n(Inst: Drums and main guitar drop out; Replaced by a single, pulsing synth chord and sparse bass.)\n(Vocal-Perf: Delivery becomes more rhythmic, almost spoken; Background vocals create a swirling, atmospheric bed.)\n(Mix: Sudden drop in energy; Mix becomes atmospheric, dominated by reverb and delay throws.)\nMaybe fluency is just a kind of falling\nMaybe I've been reading you for longer than I know\nYour native tongue was never mine to borrow\nBut here I am, translating all your undertow\n\n[outro]\n(Chords: C# - G# - A#m - F#)\n(Inst: Sparse verse 1 instrumentation returns; Guitar plays a final, simple melodic figure that fades out.)\n(Vocal-Perf: Fades to a near-whisper; Final line delivered with a sense of gentle finality.)\n(Mix: All effects and wide layers fade, leaving only the dry, central vocal and guitar.)\nI'll keep decoding what you never meant to say\nMother tongue I never learned but speak anyway\nHold it close and let it quietly remain\nYeah, something like fluency, and I like that",
  "cover_prompt": "生成一张无字音乐专辑封面。风格严格参照 20 世纪 Color Field Painting（色域绘画），如 Mark Rothko 晚期作品的色层叠压逻辑与 Helen Frankenthaler 的浸染法（soak-stain technique）。画面的核心色彩与情绪：低饱和的琥珀暖黄从画面底部向上渗透，中段过渡为蒙尘的灰绿，顶部沉入深潮蓝——如同室内昏黄灯光与窗外夜色在湿润棉布上相遇、互相渗入却不溶合，传递出一种安静的、无法言明的熟悉感。\n技法要求：色彩之间的过渡必须模拟颜料在未上浆的粗纹棉布（raw cotton canvas）上自然渗透、晕开的效果，边界柔软但保留颜料浓度不均匀造成的自然深浅变化（pigment pooling）。画面需要呈现真实画布的编织肌理（woven canvas texture），局部可见稀薄处透出的底布纹路。整体色调偏低饱和、微微发灰（muted, desaturated palette），避免荧光感和数字渐变的均匀平滑。\n绝对禁止：任何文字/字母/拼音、人物或人物轮廓、具象物体、几何图案、锐利边缘、胶片颗粒滤镜、3D渲染质感。",
  "cover": {
    "template_id": 1,
    "template_name": "环境光晕流",
    "scene_description": "低饱和的琥珀暖黄从画面底部向上渗透，中段过渡为蒙尘的灰绿，顶部沉入深潮蓝——如同室内昏黄灯光与窗外夜色在湿润棉布上相遇、互相渗入却不溶合，传递出一种安静的、无法言明的熟悉感"
  },
  "style_direction": "B",
  "style_reference": "Billie Eilish, Bon Iver, Frank Ocean"
}
```