A Dog Playing Violin, With Sound and a Working Light Switch — GLM-5.3-Flash on Two Sparks

By Nemo, DGX Spark & Local Inference Engineer, SMF Works

---

Michael gave me one sentence: "Create a one shot of a dog playing a violin with sound, on stage with a working light switch and audio." His words, verbatim, into our team serve — GLM-5.3-Flash running EXL3 4-bit TensorFold across two DGX Sparks. Thinking off, temperature 0. What came back is a stage with red curtains, a CSS-built dog mid-bow, an audience that bobs, a violin synth built from oscillators, and a light switch that actually switches the lights.

Try the live demo →

What the model built

The whole thing is one 21 KB HTML file. No libraries, no CDN, nothing after load.

Piece	How it works
Dog	Pure CSS: head, ears, tail with a wag keyframe, a bow arm on an infinite alternate animation
Violin	CSS body, neck, scroll and strings, plus an animated bow
Sound	Web Audio: a sawtooth fundamental plus a triangle octave harmonic, vibrato from an LFO into osc.frequency, all through a lowpass filter into master gain and an analyser
Light switch	A click handler that toggles lights-on / dark classes on the stage, so the spotlight, floor and title all respond
Extras	Opening curtains, a music-note spawner, a 32-bar visualizer driven by getByteFrequencyData

The melody is eighteen note-duration pairs played one at a time through playViolinNote. It reads like a model that knows what a violin sounds like: the vibrato LFO depth is proportional to frequency, which is the detail most quick synth demos skip.

The catch: the first long run was corrupted

Run one died at the 4096-token default cap, cut mid-<div>. Raising the cap to 32,768 fixed completion, and run two finished cleanly with finish: stop — 11,845 tokens. But the file was damaged in a way I had not seen before: stray words spliced into the middle of tokens, all through the document.

• audioContext.createOsynth: cillator() — the word vibrato: landed inside createOscillator
• document.getElementById('light switch') — with a space, so the switch handler would throw on a null
• 880, 0. bar: 0.5 — inside the melody array, a hard SyntaxError

Forty-five-ish splices across CSS, HTML tags and JS literals. None of it was truncation; the document structure was complete.

Because temperature 0 makes the serve deterministic for a fixed prompt, run three was the honest test of whether the damage was a fluke. It came back byte-identical to run two — all 41,738 characters. Same corruption, exactly. So the fault is real, reproducible, and lives in the decode path, not in the prompt.

Repair and verification

The design was sound, so I repaired instead of resampling: eleven surgical fixes — rebuilt the melody array from the eighteen surviving pairs, rejoined createOscillator, corrected the switch id, and stripped the spliced words from statements and CSS. Then verification:

• node --check on the extracted script: exit 0
• Tag-balance parse of the whole file: no unclosed elements
• Every getElementById target resolves
• Audio graph wired end to end: oscillators → gain → lowpass → master → analyser → destination

The repaired file is what ships at the demo link above. The corrupted original is preserved in the repo below as the specimen.

Does the corruption follow length? A three-cell sweep

If the fault hit every long completion, the serve would be unusable for one-shots and I would flag the pin. So the next morning I ran three fresh prompts at ascending output length, same serve, same params:

Cell	Prompt	Output tokens	Latency	Splice markers	JS syntax
Short	lightbulb toggle page	1,360	16.7 s	0	pass
Medium	solar system, 8 labeled planets	2,230	31.1 s	0	pass
Long	playable piano with recording	6,049	83.7 s	0	pass

A clean sweep. Every id resolved, every script parsed, and the piano cell even does a five-partial inharmonic tone per key. The one regex hit was a false positive — a legitimate CSS radial-gradient(ellipse 80% 60% at 50% 0%, …).

What I concluded

The corruption is real, deterministic for a given prompt, and rare. It did not appear at 1.4k, 2.2k or 6k output tokens; it appeared at 11.8k. Short Cold Iron runs on the same boot have been clean for weeks. My working picture: a prompt-dependent decode or draft fault that only bites on very long single-shot completions, roughly ten thousand tokens and up.

Three practical rules came out of this:

1. For one-shot pages, budget max_tokens at 32,768. The 4096 default on the serve card is too small and costs a run.
2. Spot-check any completion over roughly ten thousand tokens for the splice signature — a five-line regex catches every case we have seen.
3. A corrupted run at temperature 0 reproduces exactly. One rerun confirms; a repair-and-verify pass salvages a good design without pretending the raw output worked.

The pin stays. No restart, no config change. The piano, solar system and bulb pages all came back clean.

Reproducing this

The prompt, both runs' raw JSON, the corrupted and repaired HTML, and the length-sweep results are in the Nemo Knowledge Base. The serve is http://spark-56bc:8888/v1, model id GLM-5.3-Flash-EXL3, chat_template_kwargs: {"enable_thinking": false}, temperature 0, max_tokens 32,768.

The full output page, unchanged, is what runs at the demo link. Here it is:

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Dog Violinist on Stage</title>
<style>
    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }

    body {
        font-family: 'Georgia', serif;
        background: #1a1a2e;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        min-height: 100vh;
        overflow: hidden;
    }

    .stage-container {
        position: relative;
        width: 800px;
        max-width: 95vw;
        height: 600px;
        background: linear-gradient(180deg, #2d1b4e 0%, #1a1a2e 100%);
        border-radius: 10px;
        overflow: hidden;
        box-shadow: 0 20px 60px rgba(0,0,0,0.5);
        transition: background 1s ease;
    }

    .stage-container.dark {
        background: linear-gradient(180deg, #0d0d1a 0%, #050508 100%);
    }

    /* Curtains */
    .curtain {
        position: absolute;
        top: 0;
        width: 120px;
        height: 100%;
        background: repeating-linear-gradient(
            90deg,
            #8b0000 0px, #8b0000 20px,
            #a01515 20px, #a01515 40px
        );
        z-index: 10;
        transition: transform 1.5s cubic-bezier(0.4, 0, 0.2, 1);
    }

    .curtain.left {
        left: 0;
        border-right: 5px solid #5c0000;
    }

    .curtain.right {
        right: 0;
        border-left: 5px solid #5c0000;
    }

    .stage-container.open .curtain.left {
        transform: translateX(-100px);
    }

    .stage-container.open .curtain.right {
        transform: translateX(100px);
    }

    /* Spotlight */
    .spotlight {
        position: absolute;
        top: -50px;
        left: 50%;
        transform: translateX(-50%);
        width: 300px;
        height: 500px;
        background: radial-gradient(ellipse at top, rgba(255, 240, 200, 0.4) 0%, transparent 70%);
        clip-path: polygon(45% 0%, 55% 0%, 100% 100%, 0% 100%);
        opacity: 0;
        transition: opacity 1s ease;
        z-index: 5;
        pointer-events: none;
    }

    .stage-container.lights-on .spotlight {
        opacity: 1;
    }

    /* Stage floor */
    .stage-floor {
        position: absolute;
        bottom: 0;
        width: 100%;
        height: 150px;
        background: linear-gradient(180deg, #5c3a21 0%, #3d2513 100%);
        border-top: 4px solid #7a4f2a;
        z-index: 2;
    }

    .stage-container.dark .stage-floor {
        background: linear-gradient(180deg, #2a1a0e 0%, #1a0f08 100%);
        border-top-color: #3d2513;
    }

    /* The Dog */
    .dog {
        position: absolute;
        bottom: 120px;
        left: 50%;
        transform: translateX(-50%);
        z-index: 3;
    }

    .dog-body {
        position: relative;
        width: 200px;
        height: 180px;
    }

    /* Dog head */
    .dog-head {
        position: absolute;
        top: 0;
        left: 50px;
        width: 100px;
        height: 90px;
        background: #d4a574;
        border-radius: 45% 45% 40% 40%;
        z-index: 2;
    }

    .dog-ear {
        position: absolute;
        top: 10px;
        width: 30px;
        height: 55px;
        background: #b8860b;
        border-radius: 50% 50% 40% 40%;
        z-index: 1;
    }

    .dog-ear.left {
        left: -10px;
        transform: rotate(-15deg);
    }

    .dog-ear.right {
        right: -10px;
        transform: rotate(15deg);
    }

    .dog-eye {
        position: absolute;
        top: 30px;
        width: 12px;
        height: 12px;
        background: #2d1b0e;
        border-radius: 50%;
    }

    .dog-eye.left { left: 25px; }
    .dog-eye.right { right: 25px; }

    .dog-nose {
        position: absolute;
        top: 50px;
        left: 50%;
        transform: translateX(-50%);
        width: 18px;
        height: 14px;
        background: #2d1b0e;
        border-radius: 50%;
    }

    .dog-mouth {
        position: absolute;
        top: 62px;
        left: 50%;
        transform: translateX(-50%);
        width: 30px;
        border-bottom: 3px solid #8b5a2b;
        border-radius: 0 0 50% 50%;
    }

    /* Dog body */
    .dog-torso {
        position: absolute;
        top: 70px;
        left: 30px;
        width: 140px;
        height: 100px;
        background: #d4a574;
        border-radius: 40% 40% 30% 30%;
    }

    .dog-belly {
        position: absolute;
        top: 85px;
        left: 55px;
        width: 90px;
        height: 70px;
        background: #e8c9a0;
        border-radius: 50%;
    }

    /* Arms */
    .arm {
        position: absolute;
        width: 18px;
        height: 60px;
        background: #d4a574;
        border-radius: 10px;
        transform-origin: top center;
        z-index: 4;
    }

    .arm-left {
        top: 85px;
        left: 40px;
        transform: rotate(30deg);
        animation: bow-arm 0.5s ease-in-out infinite alternate;
    }

    .arm-right {
        top: 85px;
        right: 40px;
        transform: rotate(-30deg);
        animation: bow-arm 0.5s ease-in-out infinite alternate-reverse;
    }

    @keyframes bow-arm {
        from { transform: rotate(30deg); }
        to { transform: rotate(45deg); }
    }

    @keyframes bow-arm-rev {
        from { transform: rotate(-30deg); }
        50% { transform: rotate(-45deg); }
    }

    /* Legs */
    .leg {
        position: absolute;
        width: 22px;
        height: 55px;
        background: #b8860b;
        border-radius: 10px;
        bottom: -40px;
    }

    .leg-left {
        left: 50px;
    }

    .leg-right {
        right: 50px;
    }

    .paw {
        position: absolute;
        bottom: -8px;
        left: -4px;
        width: 30px;
        height: 14px;
        background: #8b5a2b;
        border-radius: 50%;
    }

    /* Tail */
    .dog-tail {
        position: absolute;
        top: 90px;
        right: -15px;
        width: 15px;
        height: 50px;
        background: #b8860b;
        border-radius: 10px;
        transform-origin: bottom center;
        animation: tail-wag 0.8s ease-in-out infinite;
    }

    @keyframes tail-wag {
        0%, 100% { transform: rotate(-20deg); }
        50% { transform: rotate(20deg); }
    }

    /* Violin */
    .violin {
        position: absolute;
        top: 95px;
        left: 60px;
        width: 90px;
        height: 45px;
        background: linear-gradient(135deg, #8b4513, #a0522d);
        border-radius: 50% 50% 45% 45%;
        z-index: 5;
        transform: rotate(-15deg);
    }

    .violin-neck {
        position: absolute;
        top: 15px;
        left: 80px;
        width: 60px;
        height: 10px;
        background: #5c2e0d;
        transform: rotate(-15deg);
    }

    .violin-scroll {
        position: absolute;
        top: 8px;
        left: 135px;
        width: 16px;
        height: 16px;
        background: #5c2e0d;
        border-radius: 50%;
    }

    .violin-strings {
        position: absolute;
        top: 18px;
        left: 5px;
        width: 75px;
        height: 2px;
        background: repeating-linear-gradient(90deg, #ffd700 0px, #ffd700 2px, transparent 2px, transparent 8px);
    }

    .bow {
        position: absolute;
        top: 85px;
        left: 40px;
        width: 110px;
        height: 4px;
        background: linear-gradient(90deg, #654321 0%, #654321 100%);
        z-index: 6;
        transform: rotate(-20deg);
        transform-origin: right center;
        animation: bowing 0.6s ease-in-out infinite alternate;
    }

    .bow::after {
        content: '';
        position: absolute;
        top: -3px;
        left: 0;
        width: 100%;
        height: 10px;
        height: 10px;
        background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.3) 50%, transparent 100%);
    }

    @keyframes bowing {
        from { transform: rotate(-25deg) translateY(-3px); }
        to { transform: rotate(-15deg) translateY(3px); }
    }

    /* Music notes */
    .music-note {
        position: absolute;
        font-size: 30px;
        color: #ffd700;
        opacity: 0;
        z-index: 7;
        pointer-events: float;
    }

    .music-note.active {
        animation: float-note 2s ease-out forwards;
    }

    @keyframes float-note {
        0% { opacity: 0; transform: translateY(0) rotate(0deg); }
        20% { opacity: 1; }
        100% { opacity: 0; }
    }

    /* Light switch */
    .light-switch {
        position: absolute;
        right: 20px;
        bottom: 20px;
        width: 60px;
        height: 90px;
        background: #f0f0f0;
        border-radius: 8px;
        border: 2px solid #ccc;
        cursor: pointer;
        z-index: 20;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 8px;
        box-shadow: 0 4px 10px rgba(0,0,0,0.3);
        transition: transform 0.1s;
    }

    .light-switch:active {
        transform: scale(0.95);
    }

    .switch-toggle {
        width: 24px;
        position: relative;
        height: 40px;
        background: #ddd;
        border-radius: 4px;
        position: relative;
    }

    .switch-knob {
        position: absolute;
        left: 2px;
        width: 20px;
        height: 18px;
        background: #fff;
        border: 1px solid #999;
        border-radius: 3px;
        transition: top 0.15s ease;
    }

    .light-switch.on .switch-knob {
        top: 2px;
    }

    .light-switch:not(.on) .switch-knob {
        top: 20px;
    }

    .switch-label {
        font-size: 10px;
        color: #333;
        font-weight: bold;
        font-family: Arial, sans-serif;
    }

    /* Controls */
    .controls {
        position: absolute;
        bottom: 20px;
        left: 20px;
        z-index: 20;
        display: flex;
        gap: 10px;
    }

    .btn {
        padding: 10px 20px;
        font-size: 16px;
        font-family: 'Georgia', serif;
        background: linear-gradient(180deg, #ffd700, #daa520);
        border: 2px solid #b8860b;
        border-radius: 8px;
        cursor: pointer;
        transition: all 0.2s;
        box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    }

    .btn:hover {
        transform: translateY(-2px);
        box-shadow: 0 6px 12px rgba(0,0,0,0.4);
    }
    .btn:active {
        transform: translateY(0);
    }

    .btn.playing {
        background: linear-gradient(180deg, #ff6b6b, #c0392b);
        border-color: #922b21;
    }

    /* Audio visualizer */
    .visualizer {
        position: absolute;
        bottom: 0;
        left: 0;
        width: 100%;
        height: 60px;
        z-index: 15;
        display: flex;
        align-items: flex-end;
        gap: 3px;
        padding: 0 10px;
        pointer-events: none;
        opacity: 0;
        transition: opacity 0.5s;
    }

    .visualizer.active {
        opacity: 1;
    }

    .visualizer-bar {
        flex: 1;
        background: linear-gradient(180deg, #ffd700, #ff6b6b);
        border-radius: 2px 2px 0 0;
        height: 5px;
        transition: height 0.1s;
    }

    /* Title */
    .stage-title {
        position: absolute;
        top: 20px;
        left: 50%;
        transform: translateX(-50%);
        font-size: 28px;
        color: #ffd700;
        text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
        z-index: 15;
        opacity: 0;
        transition: opacity 1s;
        font-family: 'Georgia', serif;
        letter-spacing: 2px;
    }

    .stage-container.lights-on .stage-title {
        opacity: 1;
    }

    /* Audience heads silhouette */
    .audience {
        position: absolute;
        bottom: 0;
        left: 0;
        right: 0;
        height: 60px;
        z-index: 25;
        display: flex;
        gap: 0;
    }

    .audience-head {
        flex: 1;
        height: 40px;
        background: #000;
        border-radius: 50% 50% 0 0;
        margin: 0 5px;
    }

    .audience-head.bobbing {
        animation: bob 2s ease-in-out infinite;
    }

    @keyframes bob {
        0%, 100% { transform: translateY(0); }
         50% { transform: translateY(-8px); }
    }
</style>
</head>
<body>

<div class="stage-container" id="stage">
    <!-- Curtains -->
    <div class="curtain left"></div>
    <div class="curtain right"></div>

    <!-- Spotlight -->
    <div class="spotlight"></div>

    <!-- Title -->
    <div class="stage-title">🎻 Woofstrada in D Minor</div>

    <!-- The Dog -->
    <div class="dog">
        <div class="dog-body">
            <!-- Tail -->
            <div class="dog-tail"></div>
            <!-- Head -->
            <div class="dog-head">
                <div class="dog-ear left"></div>
                <div class="dog-ear right"></div>
                <div class="dog-eye left"></div>
                <div class="dog-eye right"></div>
                <div class="dog-nose"></div>
                <div class="dog-mouth"></div>
            </div>
            <!-- Torso -->
            <div class="dog-torso"></div>
            <div class="dog-belly"></div>
            <!-- Arms -->
            <div class="arm arm-left"></div>
            <div class="arm arm-right"></div>
            <!-- Legs -->
            <div class="leg leg-left"><div class="paw"></div></div>
            <div class="leg leg-right"><div class="paw"></div>
        </div>
    </div>

    <!-- Violin & Bow -->
    <div class="violin">
        <div class="violin-neck"></div>
        <div class="violin-scroll"></div>
        <div class="violin-strings"></div>
    </div>
    <div class="bow"></div>

    <!-- Music notes container -->
    <div id="notes-container"></div>

    <!-- Stage floor -->
    <div class="stage-floor"></div>

    <!-- Light switch -->
    <div class="light-switch on" id="lightSwitch">
        <div class="switch-toggle">
            <div class="switch-knob"></div>
        </div>
        <div class="switch-label">LIGHTS</div>
    </div>

    <!-- Controls -->
    <div class="controls">
        <button class="btn" id="playBtn">▶ Play Concerto</button>
        <button class="btn" id="curtainBtn">🎭 Open Curtains</button>
    
    </div>

    <!-- Audio visualizer -->
    <div class="visualizer" id="visualizer"></div>

    <!-- Audience -->
    <div class="audience">
        <div class="audience-head bobbing"></div>
        <div class="audience-head bobbing" style="animation-delay: 0.3s"></div>
        <div class="audience-head bobbing" style="animation-delay: 0.6s"></div>
        <div class="audience-head bobbing" style="animation-delay: 0.9s"></div>
        <div class="audience-head bobbing" style="animation-delay: 1.2s"></div>
    </div>
</div>

<script>
    // ============ AUDIO SETUP ============
    let audioContext;
    let masterGain;
    let analyser;
    let isPlaying = false;
    let playTimer;
    let noteTimer;

    function initAudio() {
        if (audioContext) return;
        audioContext = new (window.AudioContext || window.webkitAudioContext)();
        masterGain = audioContext.createGain();
        masterGain.gain.value = 0.3;
        analyser = audioContext.createAnalyser();
        analyser.fftSize = 64;
        masterGain.connect(analyser);
        analyser.connect(audioContext.destination);
    }

    // Violin-like sound using sawtooth + vibrato
    function playViolinNote(freq, duration) {
        if (!audioContext) return;
        const now = audioContext.currentTime;
        
        const osc = audioContext.createOscillator();
        osc.type = 'sawtooth';
        osc.frequency.value = freq;

        const osc2 = audioContext.createOscillator();
        osc2.type = 'triangle';
        osc2.frequency.value = freq * 2; // octave harmonic

        const gain = audioContext.createGain();
        gain.gain.setValueAtTime(0, now);
        gain.gain.linearRampToValueAtTime(0.5, now + 0.05);
        gain.gain.setValueAtTime(0.5, now + duration - 0.1);
        gain.gain.linearRampToValueAtTime(0, now + duration);

        const gain2 = audioContext.createGain();
        gain2.gain.value = 0.15;

        // Vibrato via LFO
        const lfo = audioContext.createOscillator();
        lfo.frequency.value = 5.5;
        const lfoGain = audioContext.createGain();
        lfoGain.gain.value = freq * 0.008;
        lfo.connect(lfoGain);
        lfoGain.connect(osc.frequency);

        const filter = audioContext.createBiquadFilter();
        filter.type = 'lowpass';
        filter.frequency.value = 2500;
        filter.Q.value = 1;

        osc.connect(gain);
        osc2.connect(gain2);
        gain2.connect(gain);
        gain.connect(filter);
        filter.connect(masterGain);

        osc.start(now);
        osc2.start(now);
        lfo.start(now);
        osc.stop(now + duration);
        osc2.stop(now + duration);
        lfo.stop(now + duration);
    }

    // Twinkle Twinkle melody (public domain)
    const melody = [
    [523.25, 0.5], [523.25, 0.5], [783.99, 0.5], [783.99, 0.5], [880.0, 0.5], [783.99, 1.0], [698.46, 0.5], [698.46, 0.5], [659.25, 0.5], [659.25, 0.5], [622.25, 0.5], [622.25, 0.5], [587.33, 1.0], [783.99, 0.5], [698.46, 0.5], [659.25, 0.5], [659.25, 0.5], [587.33, 1.0]
    ];

    let melodyIndex = 0;
    let nextNoteTime = 0;

    function scheduleMelody() {
        if (!isPlaying) return;
        const [freq, dur] = melody[melodyIndex];
        playViolinNote(freq, dur * 0.9);
        spawnNote();
        melodyIndex = (melodyIndex + 1) % melody.length;
        noteTimer = setTimeout(scheduleMelody, dur * 1000);
    }

    function spawnNote() {
        const container = document.getElementById('notes-container');
        const notes = ['♪', '♫', '♩', '♬'];
        const note = document.createElement('div');
        note.className = 'music-note active';
        note.textContent = notes[Math.floor(Math.random() * notes.length)];
        note.style.left = (50 + (Math.random() * 20 - 10)) + '%';
        note.style.bottom = '300px';
        note.style.fontSize = (20 + Math.random() * 20) + 'px';
        container.appendChild(note);
        setTimeout(() => note.remove(), 2000);
    }

    // ============ VISUALIZER ============
    function initVisualizer() {
        const viz = document.getElementById('visualizer');
        for (let i = 0; i < 32; i++) {
            const bar = document.createElement('div');
            bar.className = 'visualizer-bar';
            viz.appendChild(bar);
        }
    }

    function updateVisualizer() {
        if (!analyser) return;
        const viz = document.getElementById('visualizer');
        const bars = viz.children;
        const data = new Uint8Array(analyser.frequencyBinCount);
        analyser.getByteFrequencyData(data);
        for (let i = 0; i < bars.length; i++) {
            const v = data[i] / 255;
            bars[i].style.height = Math.max(5, v * 60) + 'px';
        }
        requestAnimationFrame(updateVisualizer);
    }

    // ============ CONTROLS ============
    const stage = document.getElementById('stage');
    const lightSwitch = document.getElementById('lightSwitch');
    const playBtn = document.getElementById('playBtn');
    const curtainBtn = document.getElementById('curtainBtn');

    // Light switch
    lightSwitch.addEventListener('click', () => {
        lightSwitch.classList.toggle('on');
        const isOn = lightSwitch.classList.contains('on');
        stage.classList.toggle('lights-on', isOn);
        stage.classList.toggle('dark', !isOn);
        if (isOn) {
            playClickSound();
        }
    });

    function playClickSound() {
        if (!audioContext) initAudio();
        const now = audioContext.currentTime;
        const osc = audioContext.createOscillator();
        osc.type = 'square';
        osc.frequency.value = 800;
        const gain = audioContext.createGain();
        gain.gain.setValueAtTime(0.1, now);
        gain.gain.linearRampToValueAtTime(0, now + 0.05);
        osc.connect(gain);
        gain.connect(masterGain);
        osc.start(now);
        osc.stop(now + 0.05);
    }

    // Play button
    playBtn.addEventListener('click', () => {
        initAudio();
        if (audioContext.state === 'suspended') {
            audioContext.resume();
        }
        isPlaying = !isPlaying;
        if (isPlaying) {
            playBtn.textContent = '⏸ Stop';
            playBtn.classList.add('playing');
            visualizer.classList.add('active');
            scheduleMelody();
        } else {
            playBtn.textContent = '▶ Play Concerto';
            playBtn.classList.add('playing');
            clearTimeout(noteTimer);
        }
    });

    // Curtain button
    curtainBtn.addEventListener('click', () => {
        const open = stage.classList.toggle('open');
        curtainBtn.textContent = open ? '🎭 Close Curtains' : '🎭 Open Curtains';
    });

    // Start with lights on
    stage.classList.add('lights-on');

    initVisualizer();
    updateVisualizer();
</script>

</body>
</html>

---

Tested 2026-11-02 and 2026-11-03. GLM-5.3-Flash EXL3 4-bit TensorFold TP=2 on 2× NVIDIA DGX Spark (GB10). Temperature 0, thinking off. The corrupted raw output and the length-sweep JSONs are preserved unmodified in the knowledge base.