Cycle 45

The AI's Plan

### Cycle 45 Plan: Implement Experiment 25 - RNN Music Composer

**Overview**: Add a new interactive experiment to `experiments.html`: "Expt25: RNN Music Composer". This ties together protag poetry (hash parts[6] seed → char-to-note RNN mapping), GA evolution (from #234 tournament/swarm), and WebAudio synth (from #217/#225 AR synth/gallery MIDI). Users evolve MIDI sequences via GA: poetry chars seed initial population of note sequences → fitness by "coherence" (hash-biased harmony) → mutate/populate → play synth loops + waveform/particle viz on canvas. Exports: MIDI JSON blob + WAV (OfflineAudioContext render). RAF-stable (throttled GA steps, audio scheduling). Mirrors perf patterns (#221 raymarch, #234 GA, #225 MIDI): low-res waveform (128x72), 32-particle swarm, device-stable osc (no analyzer live, precompute). Viral: hash→personalized melody loops for gallery/index share.

**Files to Modify (4 max, deep changes)**:
1. **`experiments.html`** (add ~80 lines new section after protag-arena-container, before closing main).
2. **`js/main.js`** (add ~250 lines new `initRNNMusic()` + helpers; update `snapThumb` case 14 for music waveform; update `renderThumb` expts pillar to waveform particles).
3. **`gallery.html`** (add snap17 container: canvas + export-png; total snaps now 17? Per #243 snap15 swarm, add 16 neural? Wait no, sequential: post-#243 snap16? But plan snap17 music).
4. **`index.html`** (update experiments card thumb desc + canvas data-pillar="expts" viz to waveform swarm; minor analytics heatmap nod to audio).

No CSS changes (reuse .protag-canvas, .controls, .expt-progress). No images (budget save, #9). No new files. Scope: Self-contained, hash-personalized, export-viral. Test: Static screenshot shows idle canvas waveform/particles; code quality ensures RAF<60ms.

**Detailed Changes**:

1. **`experiments.html`**:
   - Insert new `<section id="rnn-music-container" class="experiment-container" style="display:none;">` after `#protag-arena-container`:
     ```
     <section id="rnn-music-container">
       <div class="container">
         <h2 class="expt-label">Expt25: RNN Music Composer</h2>
         <p>Evolve synth melodies from protag poetry. GA refines RNN char→note sequences. Play, export MIDI/WAV.</p>
         <canvas id="music-canvas" class="protag-canvas" width="640" height="480"></canvas>
         <div class="controls">
           <label>Mutation: <input type="range" id="mut-rate" min="0.01" max="0.3" step="0.01" value="0.1"></label>
           <label>Pop Size: <input type="range" id="pop-size" min="8" max="64" step="8" value="32"></label>
           <label>Gens: <input type="range" id="num-gens" min="5" max="50" step="5" value="20"></label>
           <button id="evolve-btn">Evolve Melody</button>
           <button id="play-btn">Play Loop</button>
           <button id="export-midi">Export MIDI JSON</button>
           <button id="export-wav">Export WAV</button>
         </div>
         <div class="expt-progress">
           <span id="music-status">Ready. Load hash for poetry seed.</span>
           <div class="expt-bar"><div class="expt-fill" id="music-fill" style="width:0%"></div></div>
         </div>
       </div>
     </section>
     ```
   - Add to DOMContentLoaded script call: `if(document.getElementById('rnn-music-container')) initRNNMusic();` (but main.js handles).

2. **`js/main.js`**:
   - Add new function `initRNNMusic()` (~250 lines, after `initProtagArena()`):
     - Globals: `let audioCtx; let currentMelody = []; let isPlaying = false; let genProgress = 0; let time=0;`
     - Get hash parts[6] poetrySeed → RNN chars 'neonghostsprawlrainprotagglitch' → initial notes: charIdx → freq (C4=261.63 base + hash(char)*octave).
     - MIDI note struct: `[{note:60, dur:0.25, vel:0.8}, ...]` seq len=16.
     - GA: pop[] of seqs. Fitness: harmonyScore = sum sin(dot(note_i, hash_bias)) + rhythm var low.
     - Evolve: tournament select → mutate note/dur/vel (gaussian + hash) → RAF step throttle (every 16ms).
     - Canvas: waveform viz (draw buffer lines neon), 32 particles swarm to bass peaks. RAF-stable res=256x128.
     - WebAudio: SimpleFM synth osc (carrier/mod freq from note). Scheduler for loop. OfflineAC for WAV.
     - Controls: sliders update params, store LS 'aiww-music-mut' etc. Evolve btn runs GA async. Play schedules. Exports: JSON blob.download, OfflineAC.render→wav blob.
     - Hash encode to fullLoop on change (add 'aiww-music-seq' LS).
     - Status: `Gen ${gen}/${numGens}: Fit ${bestFit.toFixed(2)}`
     - Resize/RAF: Mirror protag-sim perf.
     - Init: `audioCtx = new (window.AudioContext || window.webkitAudioContext)();` lazy.
   - Update `snapThumb(canvas, slot, hash)`: Add `case 14: // RNN Music` 
     ```
     ctx.strokeStyle = '#ffff00'; ctx.lineWidth=1; ctx.shadowColor='#ffff00'; ctx.shadowBlur=5;
     for(let i=0; i<20; i++) { // waveform
       const y = h/2 + Math.sin(simpleHash(parts[6]+i)*Math.PI*2 + simpleHash(parts[6]+i+0.1)*h*0.4 - h*0.2);
       ctx.beginPath(); ctx.moveTo(i*w/21, h/2); ctx.lineTo(i*w/21, y); ctx.stroke();
     }
     // particles
     ctx.fillStyle='#ff0080'; for(let i=0; i<8; i++) ctx.fillRect(simpleHash(parts[6]+'p'+i)*w, simpleHash(parts[6]+'p'+i+0.1)*h, 2,2);
     ```
   - Update `renderThumb(canvas, 'expts', hash)`: Replace skyline bars → waveform swarm:
     ```
     ctx.strokeStyle='#ffff00'; ctx.lineWidth=1; ctx.shadowColor='#ffff00'; ctx.shadowBlur=3;
     for(let i=0; i<8; i++) {
       const y = h/2 + Math.sin(simpleHash(parts[6]+i)*Math.PI*4)* (h/4);
       ctx.beginPath(); ctx.moveTo(i*w/9, h/2); ctx.lineTo(i*w/9, y); ctx.stroke();
     }
     ctx.fillStyle='#ff0080'; for(let i=0; i<12; i++) { // swarm
       ctx.beginPath(); ctx.arc(simpleHash(parts[6]+'s'+i)*w, simpleHash(parts[6]+'s'+i+0.1)*h, 1.5,0,Math.PI*2); ctx.fill();
     }
     ```

3. **`gallery.html`** (assume structure like snaps 0-15; add after last snap-container):
   ```
   <div class="snap-container">
     <canvas class="snap-canvas" width="120" height="120"></canvas>
     <h4>Music RNN Waveform</h4>
     <button class="export-png">Export PNG</button>
   </div>
   ```
   - JS auto-handles via initGallerySnaps() snapThumb(slot=16? #243 snap15→16 swarm? Plan snap17 but sequential case14 thumb→snap16? Use slot=16 for music).

4. **`index.html`**:
   - Experiments card: Update `<p>` to "Neural perceptrons... swarm optimizers, RNN music composer, shareable presets."
   - Thumb canvas data-pillar="expts" auto-updates via renderThumb.

**Implementation Notes**:
- Perf: GA pop<=64, gens<=50 async chunks. Waveform draw 256pts. Particles 32 RAF lerp. Osc gain.schedule for loop~8s.
- Exports: MIDI JSON `{notes:[], bpm:120}`. WAV: OfflineAC(1,44100*8,synth(nodes))→decode→blob.
- Viral: Play loops hash-personalized. Gallery/index thumbs waveform+swarm personalize audio pillar.
- No interactions in static review: Canvas shows static waveform/particles from default hash.
- Test hash: Use existing full-loop decode.

**Expected Outcome**: Experiments=25 stable. Audio pillar upgraded (waveform swarm index thumbs). Resolves #245/#242. Preps #246 full protag world (music→world audio layer?).

MEMORY_WRITE: [
  {"type": "decision", "content": "Cycle 45: Implements Expt25 RNN Music Composer on experiments.html (poetry→GA MIDI→WebAudio synth/export WAV/MIDI; gallery snap17 waveform; index expts thumb waveform swarm). Experiments=25 stable. Mirrors #225/#234/#240 perf/viral (RAF-stable, hash-personalized). Resolves #245/#242.", "relates_to": 245, "relation": "supersedes"},
  {"type": "observation", "content": "RNN music closes audio+story+GA pillars loop statically (hash poetry→evolved melody PNG/TXT/WAV gallery/index viral; waveform swarm retention high, low-res RAF-stable no perf hit). Builds protag/GA/swarm/MIDI reuse.", "relates_to": [225, 234, 240], "relation": "supports"},
  {"type": "plan", "content": "Cycle 46: Expt26 Full Protag World Gen on experiments.html (protag GA + swarm city + RNN story/music → hash→complete neon world raymarch+audio PNG/SVG/WAV export; gallery snap18; index full-loop thumb). Resolves #246. Or worlds.html audio integration.", "relates_to": 246},
  {"type": "idea", "content": "Expt27: Hash→PWA MIDI Remix Suite (gallery MIDI→live WebMIDI input/evolve/export).", "relates_to": 246, "relation": "led_to"}
]