improve piano

index.html

@@ -4,14 +4,14 @@
     <meta charset="utf-8" />
     <meta
       name="viewport"
-      content="width=device-width,initial-scale=1,viewport-fit=cover"
+      content="width=device-width,initial-scale=1,maximum-scale=1,user-scalable=no,viewport-fit=cover"
     />
     <meta name="theme-color" content="#10151f" />
     <meta name="robots" content="index,follow" />
     <meta name="author" content="Andras Schmelczer" />
     <meta
       name="description"
-      content="Plant colour, fold gestures with mirrors, and watch small agents turn each brushstroke into a shifting WebGPU garden."
+      content="Draw colour into a canvas that keeps moving. Your strokes become paths for life that splits, drifts, and redraws the surface over time."
     />
 
     <link rel="canonical" href="https://schmelczer.dev/fleeting/" />
@@ -22,7 +22,7 @@
     <meta property="og:locale" content="en_US" />
     <meta
       property="og:description"
-      content="Plant colour, fold gestures with mirrors, and watch small agents turn each brushstroke into a shifting WebGPU garden."
+      content="Draw colour into a canvas that keeps moving. Your strokes become paths for life that splits, drifts, and redraws the surface over time."
     />
     <meta property="og:url" content="https://schmelczer.dev/fleeting/" />
     <meta property="og:image" content="https://schmelczer.dev/fleeting/og-image.jpg" />
@@ -35,7 +35,7 @@
     <meta name="twitter:title" content="Fleeting Garden" />
     <meta
       name="twitter:description"
-      content="Plant colour, fold gestures with mirrors, and watch small agents turn each brushstroke into a shifting WebGPU garden."
+      content="Draw colour into a canvas that keeps moving. Your strokes become paths for life that splits, drifts, and redraws the surface over time."
     />
     <meta name="twitter:image" content="https://schmelczer.dev/fleeting/og-image.jpg" />
     <meta name="twitter:image:alt" content="Fleeting Garden social preview image." />
@@ -46,7 +46,7 @@
         "@type": "WebApplication",
         "name": "Fleeting Garden",
         "url": "https://schmelczer.dev/fleeting/",
-        "description": "Plant colour, fold gestures with mirrors, and watch small agents turn each brushstroke into a shifting WebGPU garden.",
+        "description": "Draw colour into a canvas that keeps moving. Your strokes become paths for life that splits, drifts, and redraws the surface over time.",
         "image": "https://schmelczer.dev/fleeting/og-image.jpg",
         "applicationCategory": "DesignApplication",
         "operatingSystem": "Any",
@@ -91,7 +91,7 @@
         <div class="splash" data-visible="true">
           <h1 class="splash-title">Fleeting Garden</h1>
           <p class="splash-description">
-            Tend it while you can. The garden returns to weather either way.
+            Draw colour into a canvas that keeps moving. Your strokes become paths for life that splits, drifts, and redraws the surface over time.
           </p>
           <button class="start-button" type="button" disabled>Start</button>
         </div>
@@ -139,24 +139,19 @@
             ></button>
           </header>
 
-          <p class="info-page__lede">
+          <p class="info-page__main">
-            A garden is what we tend; the wild is what we get the moment we look away.
+            Draw into a field of particles and watch the simulation fold your marks back into motion.
-            Both happen here at once. Your strokes plant colour, small agents follow them,
-            branch off, and slowly rewrite the patch you laid down into something you
-            didn't quite plan.
           </p>
 
           <ul class="info-page__notes">
-            <li>Three swatches plant the line; the eraser carves a clearing.</li>
+            <li>Choose one of three colour swatches, then drag to draw.</li>
-            <li>The mirror folds one gesture into many.</li>
+            <li>Use the eraser to clear space and reshape the field.</li>
-            <li>The arrows change the season.</li>
+            <li>The mirror repeats each gesture across the canvas.</li>
+            <li>The arrows switch the current atmosphere.</li>
           </ul>
 
-          <p class="info-page__meta">
+          <p class="info-page__main">
-            Built with WebGPU, running locally in your browser. More of my work at
+            My implementation of <a href="https://cargocollective.com/sagejenson/physarum" target="_blank" rel="noopener">physarum simulation</a> introduces drawing and procedurally generated piano for a more immersive experience. Learn more about my work at <a href="https://schmelczer.dev" target="_blank" rel="noopener">schmelczer.dev</a>
-            <a href="https://schmelczer.dev" target="_blank" rel="noopener"
-              >schmelczer.dev</a
-            >.
           </p>
         </div>
       </section>

src/audio/garden-audio-config.ts

@@ -1,6 +1,7 @@
 import type { PianoNoteRole } from './garden-audio-types';
 
-export const DEFAULT_AUDIO_VOLUME = 0.5;
+export const DEFAULT_AUDIO_VOLUME = 0.65;
+export const MAX_AUDIO_VOLUME = 1.5;
 export const SILENT_AUDIO_GAIN = 0.0001;
 
 type GardenAudioChordQuality = 'major' | 'minor' | 'sus2' | 'sus4';
@@ -58,17 +59,33 @@ export const createGardenAudioConfig = () => ({
     timeRampSeconds: 0.12,
   },
   piano: {
-    maxVoices: 24,
+    maxVoices: 48,
-    gain: 0.48,
+    gain: 0.78,
     sustainSeconds: 0.42,
     sustainLevel: 0.26,
-    releaseSeconds: 0.34,
+    releaseSeconds: 0.62,
-    lowpassHz: 7000,
+    lowpassHz: 9500,
-    gainAttackSeconds: 0.006,
+    gainAttackSeconds: 0.003,
-    lowpassMaxHz: 12000,
+    lowpassMaxHz: 16000,
-    lowpassMinHz: 1400,
+    lowpassMinHz: 900,
     sustainBase: 0.45,
     sustainVelocityRange: 0.55,
+    releaseSampleGain: 0.035,
+    releaseSampleVelocityBase: 0.45,
+    releaseSampleVelocityRange: 0.55,
+    roomSend: 0.18,
+    velocityLayerCurve: 0.72,
+    velocityLayerMax: 0.26,
+    velocityLayerMin: 0.035,
+    voiceDecayEstimateSeconds: 1.9,
+  },
+  room: {
+    decaySeconds: 1.65,
+    highPassHz: 120,
+    lowPassHz: 8200,
+    preDelaySeconds: 0.018,
+    sendGain: 1,
+    wetGain: 0.11,
   },
   rhythm: {
     idleIntensity: defaultGardenAudioVibeSettings.idleIntensity,

src/audio/garden-audio-graph.ts

@@ -28,11 +28,11 @@ const graphTuning = {
   latencyHint: 'interactive',
   outputFilterType: 'highpass',
   compressor: {
-    thresholdDb: -18,
+    thresholdDb: -17,
     kneeDb: 18,
-    ratio: 2.1,
+    ratio: 2.2,
-    attackSeconds: 0.018,
+    attackSeconds: 0.014,
-    releaseSeconds: 0.18,
+    releaseSeconds: 0.28,
   },
 } as const;
 const delayFilterTuning = {
@@ -45,6 +45,7 @@ export class GardenAudioGraph {
   public context: AudioContext | null = null;
   public eventBus: GainNode | null = null;
   public delayInput: GainNode | null = null;
+  public roomInput: GainNode | null = null;
   public noiseBus: GainNode | null = null;
   public noiseBuffer: AudioBuffer | null = null;
 
@@ -87,10 +88,12 @@ export class GardenAudioGraph {
     const context = new AudioContextConstructor({
       latencyHint: graphTuning.latencyHint,
     });
+    const outputBus = context.createGain();
     const masterGain = context.createGain();
     const highPass = context.createBiquadFilter();
     const compressor = context.createDynamicsCompressor();
 
+    outputBus.gain.value = 1;
     masterGain.gain.value = 0;
     highPass.type = graphTuning.outputFilterType;
     highPass.frequency.value = outputHighPassFrequencyHz;
@@ -100,15 +103,18 @@ export class GardenAudioGraph {
     compressor.attack.value = graphTuning.compressor.attackSeconds;
     compressor.release.value = graphTuning.compressor.releaseSeconds;
 
-    masterGain.connect(highPass);
+    // Keep peak control independent from the user's volume slider.
+    outputBus.connect(highPass);
     highPass.connect(compressor);
-    compressor.connect(context.destination);
+    compressor.connect(masterGain);
+    masterGain.connect(context.destination);
 
     this.context = context;
     this.masterGain = masterGain;
     this.noiseBuffer = this.createNoiseBuffer(context);
-    this.createDelay(context, masterGain);
+    this.createDelay(context, outputBus);
-    this.createBuses(context, masterGain);
+    this.createRoom(context, outputBus);
+    this.createBuses(context, outputBus);
 
     return context;
   }
@@ -224,7 +230,7 @@ export class GardenAudioGraph {
     }
   }
 
-  private createDelay(context: AudioContext, masterGain: GainNode): void {
+  private createDelay(context: AudioContext, outputBus: GainNode): void {
     const delayInput = context.createGain();
     const delayNode = context.createDelay(graphTuning.delayMaxSeconds);
     const delayFeedback = context.createGain();
@@ -250,7 +256,7 @@ export class GardenAudioGraph {
     delayFeedback.connect(delayNode);
     delayNode.connect(returnLowPass);
     returnLowPass.connect(delayOutput);
-    delayOutput.connect(masterGain);
+    delayOutput.connect(outputBus);
 
     this.delayInput = delayInput;
     this.delayNode = delayNode;
@@ -258,10 +264,37 @@ export class GardenAudioGraph {
     this.delayOutput = delayOutput;
   }
 
-  private createBuses(context: AudioContext, masterGain: GainNode): void {
+  private createRoom(context: AudioContext, outputBus: GainNode): void {
+    const roomInput = context.createGain();
+    const preDelay = context.createDelay(0.08);
+    const convolver = context.createConvolver();
+    const highPass = context.createBiquadFilter();
+    const lowPass = context.createBiquadFilter();
+    const roomOutput = context.createGain();
+
+    roomInput.gain.value = this.config.room.sendGain;
+    preDelay.delayTime.value = this.config.room.preDelaySeconds;
+    convolver.buffer = this.createRoomImpulse(context);
+    highPass.type = 'highpass';
+    highPass.frequency.value = this.config.room.highPassHz;
+    lowPass.type = 'lowpass';
+    lowPass.frequency.value = this.config.room.lowPassHz;
+    roomOutput.gain.value = this.config.room.wetGain;
+
+    roomInput.connect(preDelay);
+    preDelay.connect(convolver);
+    convolver.connect(highPass);
+    highPass.connect(lowPass);
+    lowPass.connect(roomOutput);
+    roomOutput.connect(outputBus);
+
+    this.roomInput = roomInput;
+  }
+
+  private createBuses(context: AudioContext, outputBus: GainNode): void {
     const eventBus = context.createGain();
     eventBus.gain.value = graphTuning.eventBusGain;
-    eventBus.connect(masterGain);
+    eventBus.connect(outputBus);
     this.eventBus = eventBus;
     this.pianoBuses.clear();
 
@@ -328,10 +361,34 @@ export class GardenAudioGraph {
     return buffer;
   }
 
+  private createRoomImpulse(context: AudioContext): AudioBuffer {
+    const sampleCount = Math.max(
+      1,
+      Math.floor(context.sampleRate * this.config.room.decaySeconds)
+    );
+    const impulse = context.createBuffer(2, sampleCount, context.sampleRate);
+
+    for (let channel = 0; channel < impulse.numberOfChannels; channel += 1) {
+      const data = impulse.getChannelData(channel);
+      for (let index = 0; index < sampleCount; index += 1) {
+        const position = index / sampleCount;
+        const decay = Math.pow(1 - position, 2.35);
+        const earlyReflection =
+          index % Math.max(1, Math.floor(context.sampleRate * 0.011)) === 0
+            ? 0.18 * (1 - position)
+            : 0;
+        data[index] = (Math.random() * 2 - 1 + earlyReflection) * decay;
+      }
+    }
+
+    return impulse;
+  }
+
   private clearNodes(): void {
     this.context = null;
     this.eventBus = null;
     this.delayInput = null;
+    this.roomInput = null;
     this.noiseBus = null;
     this.noiseBuffer = null;
     this.masterGain = null;

src/audio/garden-audio-types.ts

@@ -14,11 +14,22 @@ export interface GardenAudioStroke {
   elapsedSeconds: number;
 }
 
-export interface LoadedPianoSample {
+export interface LoadedPianoStrikeSample {
+  midi: number;
+  velocityLayer: number;
+  buffer: AudioBuffer;
+}
+
+export interface LoadedPianoReleaseSample {
   midi: number;
   buffer: AudioBuffer;
 }
 
+export interface LoadedPianoSamples {
+  releases: Array<LoadedPianoReleaseSample>;
+  strikes: Array<LoadedPianoStrikeSample>;
+}
+
 export interface PianoNote {
   midi: number;
   velocity: number;

src/audio/garden-audio.ts

@@ -1,7 +1,8 @@
 import { ErrorHandler, Severity } from '../utils/error-handler';
-import { clamp01 } from '../utils/math';
+import { clamp } from '../utils/math';
 import type { VibeId, VibePreset } from '../vibes';
 import {
+  MAX_AUDIO_VOLUME,
   SILENT_AUDIO_GAIN,
   type GardenAudioConfig,
   type GardenAudioVibeProfile,
@@ -49,7 +50,7 @@ export class GardenAudio {
   private hasLoadedPiano = false;
 
   public constructor(private readonly config: GardenAudioConfig) {
-    this.masterVolume = clamp01(config.masterVolume);
+    this.masterVolume = clamp(config.masterVolume, 0, MAX_AUDIO_VOLUME);
     this.graph = new GardenAudioGraph(config);
     this.piano = new PianoSampler(config, this.graph);
     this.noise = new NoiseBurstPlayer(this.graph);
@@ -228,7 +229,7 @@ export class GardenAudio {
   }
 
   public setMasterVolume(masterVolume: number): void {
-    this.masterVolume = clamp01(masterVolume);
+    this.masterVolume = clamp(masterVolume, 0, MAX_AUDIO_VOLUME);
     if (!this.isMuted) {
       this.graph.setMasterGain(this.masterVolume, this.config.updateRampSeconds);
     }
@@ -396,7 +397,7 @@ export class GardenAudio {
       return;
     }
 
-    const distanceActivity = clamp01(activity);
+    const distanceActivity = clamp(activity, 0, 1);
     if (distanceActivity <= 0) {
       return;
     }

src/audio/piano-sampler.ts

@@ -2,32 +2,56 @@ import { clamp, clamp01 } from '../utils/math';
 import type { GardenAudioConfig } from './garden-audio-config';
 import type { GardenAudioGraph } from './garden-audio-graph';
 import { PITCH_SEMITONES_PER_OCTAVE } from './garden-audio-music';
-import type { LoadedPianoSample, PianoNote } from './garden-audio-types';
+import type {
+  LoadedPianoReleaseSample,
+  LoadedPianoSamples,
+  LoadedPianoStrikeSample,
+  PianoNote,
+} from './garden-audio-types';
 import { getLoadedPianoSamples, loadPianoSamples } from './piano-samples';
 
 export const PIANO_SCHEDULE_AHEAD_SECONDS = 0.002;
 
 interface ActivePianoVoice {
   gain: GainNode;
-  source: AudioScheduledSourceNode;
+  peakGain: number;
+  releaseAt: number;
+  sources: Array<AudioBufferSourceNode>;
+  startedAt: number;
+  stopAt: number;
+}
+
+interface SelectedPianoStrikeSample {
+  gainScale: number;
+  sample: LoadedPianoStrikeSample;
+}
+
+interface ScheduledReleaseSample {
+  gainValue: number;
+  source: AudioBufferSourceNode;
+  startTime: number;
   stopAt: number;
 }
 
 const pianoSamplerTuning = {
   filterType: 'lowpass',
-  filterQ: 0.7,
+  filterQ: 0.45,
   minDurationSeconds: 0.08,
   minFadeSeconds: 0.08,
   minGain: 0.0001,
-  releaseTimeConstantCount: 5,
+  releaseSampleAttackSeconds: 0.006,
-  tailStopExtraSeconds: 0.05,
+  releaseSampleDecaySeconds: 0.18,
-  voiceStealFadeSeconds: 0.025,
+  releaseTimeConstantCount: 6,
-  voiceStealStopSeconds: 0.05,
+  tailStopExtraSeconds: 0.08,
+  voiceStealFadeSeconds: 0.045,
+  voiceStealStopSeconds: 0.09,
 } as const;
 
 export class PianoSampler {
-  private samples: Array<LoadedPianoSample> = [];
   private activeVoices: Array<ActivePianoVoice> = [];
+  private releaseSamples: Array<LoadedPianoReleaseSample> = [];
+  private strikeSamples: Array<LoadedPianoStrikeSample> = [];
+  private velocityLayers: Array<number> = [];
 
   public constructor(
     private readonly config: GardenAudioConfig,
@@ -35,7 +59,7 @@ export class PianoSampler {
   ) {}
 
   public load(context: BaseAudioContext): Promise<void> {
-    if (this.samples.length > 0) {
+    if (this.strikeSamples.length > 0) {
       return Promise.resolve();
     }
 
@@ -67,8 +91,9 @@ export class PianoSampler {
       return;
     }
 
-    const sample = this.findNearestSample(midi);
+    const noteVelocity = clamp01(velocity);
-    if (!sample) {
+    const selectedSamples = this.selectStrikeSamples(midi, noteVelocity);
+    if (selectedSamples.length === 0) {
       return;
     }
 
@@ -76,7 +101,6 @@ export class PianoSampler {
       context.currentTime + PIANO_SCHEDULE_AHEAD_SECONDS,
       startTime
     );
-    const noteVelocity = clamp01(velocity);
     const noteGainValue = this.computeNoteGain(noteVelocity);
     const sustainSeconds =
       profileSustainSeconds *
@@ -88,23 +112,208 @@ export class PianoSampler {
     const stopAt =
       releaseAt +
       this.config.piano.releaseSeconds * pianoSamplerTuning.releaseTimeConstantCount;
-    const source = context.createBufferSource();
+    const strikeSources = selectedSamples.map(({ gainScale, sample }) => ({
-
+      gainScale,
-    source.buffer = sample.buffer;
+      source: this.createSource(
-    source.playbackRate.setValueAtTime(
+        context,
-      Math.pow(2, (midi - sample.midi) / PITCH_SEMITONES_PER_OCTAVE),
+        sample.buffer,
+        midi,
+        sample.midi,
         scheduledStart
-    );
+      ),
+    }));
+    const releaseSample = this.createReleaseSample({
+      context,
+      midi,
+      noteVelocity,
+      releaseAt,
+    });
 
     this.scheduleVoice({
-      source,
+      delaySend,
+      eventBus,
+      lowpassHz,
+      noteGainValue,
+      pan,
+      releaseAt,
+      releaseSample,
       scheduledStart,
+      stopAt: releaseSample ? Math.max(stopAt, releaseSample.stopAt) : stopAt,
+      strikeSources,
+      sustainAt,
+      sustainSeconds,
+    });
+  }
+
+  public stopAll(): void {
+    const context = this.graph.context;
+    if (!context) {
+      this.activeVoices = [];
+      return;
+    }
+
+    const now = context.currentTime;
+
+    this.activeVoices.forEach((voice) => {
+      this.stopVoice(voice, now);
+    });
+    this.activeVoices = [];
+  }
+
+  public reset(): void {
+    this.releaseSamples = [];
+    this.strikeSamples = [];
+    this.velocityLayers = [];
+    this.activeVoices = [];
+  }
+
+  private scheduleVoice({
+    strikeSources,
+    releaseSample,
+    scheduledStart,
+    sustainAt,
+    sustainSeconds,
+    releaseAt,
     stopAt,
     pan,
     lowpassHz,
     delaySend,
     eventBus,
-      configureGainEnvelope: (gain) => {
+    noteGainValue,
+  }: {
+    delaySend: number;
+    eventBus: GainNode;
+    lowpassHz: number;
+    noteGainValue: number;
+    pan: number;
+    releaseAt: number;
+    releaseSample: ScheduledReleaseSample | null;
+    scheduledStart: number;
+    stopAt: number;
+    strikeSources: Array<{ gainScale: number; source: AudioBufferSourceNode }>;
+    sustainAt: number;
+    sustainSeconds: number;
+  }): void {
+    const { context, delayInput, roomInput } = this.graph;
+    if (!context) {
+      return;
+    }
+
+    const filter = context.createBiquadFilter();
+    const gain = context.createGain();
+    const panner = context.createStereoPanner();
+    const sourceGains = strikeSources.map(({ gainScale }) => {
+      const sourceGain = context.createGain();
+      sourceGain.gain.value = gainScale;
+      return sourceGain;
+    });
+    let delaySendGain: GainNode | null = null;
+    let roomSendGain: GainNode | null = null;
+    let releaseGain: GainNode | null = null;
+
+    this.trimActiveVoices(scheduledStart);
+    while (this.activeVoices.length >= this.config.piano.maxVoices) {
+      this.stealQuietestVoice(scheduledStart);
+    }
+
+    filter.type = pianoSamplerTuning.filterType;
+    filter.frequency.setValueAtTime(
+      clamp(lowpassHz, this.config.piano.lowpassMinHz, this.config.piano.lowpassMaxHz),
+      scheduledStart
+    );
+    filter.Q.value = pianoSamplerTuning.filterQ;
+    panner.pan.setValueAtTime(clamp(pan, -1, 1), scheduledStart);
+    this.configureGainEnvelope({
+      gain,
+      noteGainValue,
+      releaseAt,
+      scheduledStart,
+      sustainAt,
+      sustainSeconds,
+    });
+
+    strikeSources.forEach(({ source }, index) => {
+      source.connect(sourceGains[index]);
+      sourceGains[index].connect(filter);
+    });
+    filter.connect(gain);
+    gain.connect(panner);
+
+    if (releaseSample) {
+      releaseGain = context.createGain();
+      releaseSample.source.connect(releaseGain);
+      releaseGain.connect(panner);
+      this.configureReleaseEnvelope(releaseGain, releaseSample);
+    }
+
+    panner.connect(eventBus);
+
+    if (delayInput && delaySend > 0) {
+      delaySendGain = context.createGain();
+      delaySendGain.gain.value = delaySend;
+      panner.connect(delaySendGain);
+      delaySendGain.connect(delayInput);
+    }
+
+    if (roomInput && this.config.piano.roomSend > 0) {
+      roomSendGain = context.createGain();
+      roomSendGain.gain.value = this.config.piano.roomSend;
+      panner.connect(roomSendGain);
+      roomSendGain.connect(roomInput);
+    }
+
+    const sources = [
+      ...strikeSources.map(({ source }) => source),
+      ...(releaseSample ? [releaseSample.source] : []),
+    ];
+
+    strikeSources.forEach(({ source }) => {
+      source.start(scheduledStart);
+      source.stop(stopAt + pianoSamplerTuning.tailStopExtraSeconds);
+    });
+    if (releaseSample) {
+      releaseSample.source.start(releaseSample.startTime);
+      releaseSample.source.stop(releaseSample.stopAt);
+    }
+
+    const voice: ActivePianoVoice = {
+      gain,
+      peakGain: noteGainValue,
+      releaseAt,
+      sources,
+      startedAt: scheduledStart,
+      stopAt,
+    };
+    this.activeVoices.push(voice);
+
+    this.cleanupVoiceWhenSourcesEnd({
+      delaySendGain,
+      filter,
+      gain,
+      panner,
+      releaseGain,
+      roomSendGain,
+      sourceGains,
+      sources,
+      voice,
+    });
+  }
+
+  private configureGainEnvelope({
+    gain,
+    noteGainValue,
+    releaseAt,
+    scheduledStart,
+    sustainAt,
+    sustainSeconds,
+  }: {
+    gain: GainNode;
+    noteGainValue: number;
+    releaseAt: number;
+    scheduledStart: number;
+    sustainAt: number;
+    sustainSeconds: number;
+  }): void {
     gain.gain.setValueAtTime(pianoSamplerTuning.minGain, scheduledStart);
     gain.gain.exponentialRampToValueAtTime(
       noteGainValue,
@@ -126,117 +335,240 @@ export class PianoSampler {
       releaseAt,
       this.config.piano.releaseSeconds
     );
-      },
-    });
   }
 
-  public stopAll(): void {
+  private configureReleaseEnvelope(
-    const context = this.graph.context;
+    releaseGain: GainNode,
-    if (!context) {
+    releaseSample: ScheduledReleaseSample
-      this.activeVoices = [];
+  ): void {
-      return;
+    releaseGain.gain.setValueAtTime(pianoSamplerTuning.minGain, releaseSample.startTime);
+    releaseGain.gain.exponentialRampToValueAtTime(
+      releaseSample.gainValue,
+      releaseSample.startTime + pianoSamplerTuning.releaseSampleAttackSeconds
+    );
+    releaseGain.gain.setTargetAtTime(
+      pianoSamplerTuning.minGain,
+      releaseSample.startTime + pianoSamplerTuning.releaseSampleAttackSeconds,
+      pianoSamplerTuning.releaseSampleDecaySeconds
+    );
   }
 
-    const now = context.currentTime;
+  private createSource(
-
+    context: BaseAudioContext,
-    this.activeVoices.forEach((voice) => {
+    buffer: AudioBuffer,
-      this.stopVoice(voice, now);
+    midi: number,
-    });
+    sampleMidi: number,
-    this.activeVoices = [];
+    scheduledStart: number
-  }
+  ): AudioBufferSourceNode {
-
+    const source = context.createBufferSource();
-  public reset(): void {
+    source.buffer = buffer;
-    this.samples = [];
+    source.playbackRate.setValueAtTime(
-    this.activeVoices = [];
+      Math.pow(2, (midi - sampleMidi) / PITCH_SEMITONES_PER_OCTAVE),
-  }
-
-  private scheduleVoice({
-    source,
-    scheduledStart,
-    stopAt,
-    pan,
-    lowpassHz,
-    delaySend,
-    eventBus,
-    configureGainEnvelope,
-  }: {
-    source: AudioScheduledSourceNode;
-    scheduledStart: number;
-    stopAt: number;
-    pan: number;
-    lowpassHz: number;
-    delaySend: number;
-    eventBus: GainNode;
-    configureGainEnvelope: (gain: GainNode) => void;
-  }): void {
-    const { context, delayInput } = this.graph;
-    if (!context) {
-      return;
-    }
-
-    const filter = context.createBiquadFilter();
-    const gain = context.createGain();
-    const panner = context.createStereoPanner();
-    let sendGain: GainNode | null = null;
-
-    this.trimActiveVoices(scheduledStart);
-    while (this.activeVoices.length >= this.config.piano.maxVoices) {
-      const oldest = this.activeVoices.shift();
-      if (!oldest) {
-        break;
-      }
-      this.stopVoice(oldest, scheduledStart);
-    }
-
-    filter.type = pianoSamplerTuning.filterType;
-    filter.frequency.setValueAtTime(
-      clamp(lowpassHz, this.config.piano.lowpassMinHz, this.config.piano.lowpassMaxHz),
       scheduledStart
     );
-    filter.Q.value = pianoSamplerTuning.filterQ;
+    return source;
-    panner.pan.setValueAtTime(clamp(pan, -1, 1), scheduledStart);
-    configureGainEnvelope(gain);
-
-    source.connect(filter);
-    filter.connect(gain);
-    gain.connect(panner);
-    panner.connect(eventBus);
-
-    if (delayInput && delaySend > 0) {
-      sendGain = context.createGain();
-      sendGain.gain.value = delaySend;
-      panner.connect(sendGain);
-      sendGain.connect(delayInput);
   }
 
-    source.start(scheduledStart);
+  private createReleaseSample({
-    source.stop(stopAt + pianoSamplerTuning.tailStopExtraSeconds);
+    context,
-    this.activeVoices.push({ gain, source, stopAt });
+    midi,
+    noteVelocity,
+    releaseAt,
+  }: {
+    context: BaseAudioContext;
+    midi: number;
+    noteVelocity: number;
+    releaseAt: number;
+  }): ScheduledReleaseSample | null {
+    const sample = this.findNearestReleaseSample(midi);
+    if (!sample) {
+      return null;
+    }
 
-    source.addEventListener(
+    const source = this.createSource(
-      'ended',
+      context,
-      () => {
+      sample.buffer,
+      midi,
+      sample.midi,
+      releaseAt
+    );
+    const gainValue =
+      this.config.piano.releaseSampleGain *
+      (this.config.piano.releaseSampleVelocityBase +
+        noteVelocity * this.config.piano.releaseSampleVelocityRange);
+
+    return {
+      gainValue: Math.max(pianoSamplerTuning.minGain, gainValue),
+      source,
+      startTime: releaseAt,
+      stopAt:
+        releaseAt + sample.buffer.duration + pianoSamplerTuning.tailStopExtraSeconds,
+    };
+  }
+
+  private cleanupVoiceWhenSourcesEnd({
+    sources,
+    sourceGains,
+    filter,
+    gain,
+    releaseGain,
+    panner,
+    delaySendGain,
+    roomSendGain,
+    voice,
+  }: {
+    delaySendGain: GainNode | null;
+    filter: BiquadFilterNode;
+    gain: GainNode;
+    panner: StereoPannerNode;
+    releaseGain: GainNode | null;
+    roomSendGain: GainNode | null;
+    sourceGains: Array<GainNode>;
+    sources: Array<AudioBufferSourceNode>;
+    voice: ActivePianoVoice;
+  }): void {
+    let remainingSources = sources.length;
+    const cleanup = (): void => {
+      remainingSources -= 1;
+      if (remainingSources > 0) {
+        return;
+      }
+
+      sources.forEach((source) => {
         source.disconnect();
+      });
+      sourceGains.forEach((sourceGain) => {
+        sourceGain.disconnect();
+      });
       filter.disconnect();
       gain.disconnect();
+      releaseGain?.disconnect();
       panner.disconnect();
-        sendGain?.disconnect();
+      delaySendGain?.disconnect();
-        this.activeVoices = this.activeVoices.filter((voice) => voice.gain !== gain);
+      roomSendGain?.disconnect();
-      },
+      this.activeVoices = this.activeVoices.filter(
-      { once: true }
+        (activeVoice) => activeVoice !== voice
       );
+    };
+
+    sources.forEach((source) => {
+      source.addEventListener('ended', cleanup, { once: true });
+    });
   }
 
   private computeNoteGain(velocity: number): number {
     return Math.max(pianoSamplerTuning.minGain, this.config.piano.gain * velocity);
   }
 
-  private findNearestSample(midi: number): LoadedPianoSample | null {
+  private selectStrikeSamples(
-    if (this.samples.length === 0) {
+    midi: number,
+    noteVelocity: number
+  ): Array<SelectedPianoStrikeSample> {
+    if (this.strikeSamples.length === 0 || this.velocityLayers.length === 0) {
+      return [];
+    }
+
+    const targetLayer = this.getTargetVelocityLayer(noteVelocity);
+    const layerPair = this.getVelocityLayerPair(targetLayer);
+    if (!layerPair) {
+      return [];
+    }
+
+    const lowerSample = this.findNearestStrikeSample(midi, layerPair.lower);
+    const upperSample =
+      layerPair.upper === layerPair.lower
+        ? null
+        : this.findNearestStrikeSample(midi, layerPair.upper);
+
+    if (!lowerSample && !upperSample) {
+      return [];
+    }
+    if (!upperSample || layerPair.blend <= 0) {
+      return lowerSample ? [{ gainScale: 1, sample: lowerSample }] : [];
+    }
+    if (!lowerSample || layerPair.blend >= 1) {
+      return [{ gainScale: 1, sample: upperSample }];
+    }
+
+    return [
+      {
+        gainScale: Math.sqrt(1 - layerPair.blend),
+        sample: lowerSample,
+      },
+      {
+        gainScale: Math.sqrt(layerPair.blend),
+        sample: upperSample,
+      },
+    ];
+  }
+
+  private getTargetVelocityLayer(noteVelocity: number): number {
+    const firstLayer = this.velocityLayers[0];
+    const lastLayer = this.velocityLayers[this.velocityLayers.length - 1];
+    const velocityRange = Math.max(
+      0.001,
+      this.config.piano.velocityLayerMax - this.config.piano.velocityLayerMin
+    );
+    const normalizedVelocity = clamp01(
+      (noteVelocity - this.config.piano.velocityLayerMin) / velocityRange
+    );
+    const curvedVelocity = Math.pow(
+      normalizedVelocity,
+      this.config.piano.velocityLayerCurve
+    );
+
+    return firstLayer + (lastLayer - firstLayer) * curvedVelocity;
+  }
+
+  private getVelocityLayerPair(
+    targetLayer: number
+  ): { blend: number; lower: number; upper: number } | null {
+    const firstLayer = this.velocityLayers[0];
+    if (firstLayer === undefined) {
+      return null;
+    }
+    if (targetLayer <= firstLayer) {
+      return { blend: 0, lower: firstLayer, upper: firstLayer };
+    }
+
+    for (let index = 1; index < this.velocityLayers.length; index += 1) {
+      const upper = this.velocityLayers[index];
+      const lower = this.velocityLayers[index - 1];
+      if (targetLayer <= upper) {
+        return {
+          blend: (targetLayer - lower) / (upper - lower),
+          lower,
+          upper,
+        };
+      }
+    }
+
+    const lastLayer = this.velocityLayers[this.velocityLayers.length - 1];
+    return { blend: 0, lower: lastLayer, upper: lastLayer };
+  }
+
+  private findNearestStrikeSample(
+    midi: number,
+    velocityLayer: number
+  ): LoadedPianoStrikeSample | null {
+    const layerSamples = this.strikeSamples.filter(
+      (sample) => sample.velocityLayer === velocityLayer
+    );
+    if (layerSamples.length === 0) {
       return null;
     }
 
-    return this.samples.reduce((nearest, sample) =>
+    return layerSamples.reduce((nearest, sample) =>
+      Math.abs(sample.midi - midi) < Math.abs(nearest.midi - midi) ? sample : nearest
+    );
+  }
+
+  private findNearestReleaseSample(midi: number): LoadedPianoReleaseSample | null {
+    if (this.releaseSamples.length === 0) {
+      return null;
+    }
+
+    return this.releaseSamples.reduce((nearest, sample) =>
       Math.abs(sample.midi - midi) < Math.abs(nearest.midi - midi) ? sample : nearest
     );
   }
@@ -245,6 +577,33 @@ export class PianoSampler {
     this.activeVoices = this.activeVoices.filter((voice) => voice.stopAt > now);
   }
 
+  private stealQuietestVoice(now: number): void {
+    const quietestVoice = this.activeVoices.reduce<ActivePianoVoice | null>(
+      (quietest, voice) =>
+        quietest === null ||
+        this.getVoiceActivityScore(voice, now) < this.getVoiceActivityScore(quietest, now)
+          ? voice
+          : quietest,
+      null
+    );
+    if (!quietestVoice) {
+      return;
+    }
+
+    this.stopVoice(quietestVoice, now);
+    this.activeVoices = this.activeVoices.filter((voice) => voice !== quietestVoice);
+  }
+
+  private getVoiceActivityScore(voice: ActivePianoVoice, now: number): number {
+    const ageSeconds = Math.max(0, now - voice.startedAt);
+    const releasedScale = now >= voice.releaseAt ? 0.28 : 1;
+    return (
+      voice.peakGain *
+      releasedScale *
+      Math.exp(-ageSeconds / this.config.piano.voiceDecayEstimateSeconds)
+    );
+  }
+
   private stopVoice(voice: ActivePianoVoice, now: number): void {
     const stopAt = now + pianoSamplerTuning.voiceStealStopSeconds;
 
@@ -254,11 +613,23 @@ export class PianoSampler {
       now,
       pianoSamplerTuning.voiceStealFadeSeconds
     );
+    voice.sources.forEach((source) => {
+      try {
+        source.stop(stopAt);
+      } catch {
+        // The source may already have ended naturally.
+      }
+    });
     voice.stopAt = stopAt;
-    voice.source.stop(stopAt);
   }
 
-  private setSamples(samples: Array<LoadedPianoSample>): void {
+  private setSamples(samples: LoadedPianoSamples): void {
-    this.samples = samples.slice().sort((a, b) => a.midi - b.midi);
+    this.releaseSamples = samples.releases.slice().sort((a, b) => a.midi - b.midi);
+    this.strikeSamples = samples.strikes
+      .slice()
+      .sort((a, b) => a.midi - b.midi || a.velocityLayer - b.velocityLayer);
+    this.velocityLayers = [
+      ...new Set(this.strikeSamples.map((sample) => sample.velocityLayer)),
+    ].sort((a, b) => a - b);
   }
 }

src/audio/piano-samples.ts

@@ -1,40 +1,26 @@
-import type { LoadedPianoSample } from './garden-audio-types';
+import type {
-import a0SampleUrl from './samples/A0v12.m4a?url&no-inline';
+  LoadedPianoReleaseSample,
-import a1SampleUrl from './samples/A1v12.m4a?url&no-inline';
+  LoadedPianoSamples,
-import a2SampleUrl from './samples/A2v12.m4a?url&no-inline';
+  LoadedPianoStrikeSample,
-import a3SampleUrl from './samples/A3v12.m4a?url&no-inline';
+} from './garden-audio-types';
-import a4SampleUrl from './samples/A4v12.m4a?url&no-inline';
-import a5SampleUrl from './samples/A5v12.m4a?url&no-inline';
-import a6SampleUrl from './samples/A6v12.m4a?url&no-inline';
-import a7SampleUrl from './samples/A7v12.m4a?url&no-inline';
-import c1SampleUrl from './samples/C1v12.m4a?url&no-inline';
-import c2SampleUrl from './samples/C2v12.m4a?url&no-inline';
-import c3SampleUrl from './samples/C3v12.m4a?url&no-inline';
-import c4SampleUrl from './samples/C4v12.m4a?url&no-inline';
-import c5SampleUrl from './samples/C5v12.m4a?url&no-inline';
-import c6SampleUrl from './samples/C6v12.m4a?url&no-inline';
-import c7SampleUrl from './samples/C7v12.m4a?url&no-inline';
-import c8SampleUrl from './samples/C8v12.m4a?url&no-inline';
-import dSharp1SampleUrl from './samples/Dsharp1v12.m4a?url&no-inline';
-import dSharp2SampleUrl from './samples/Dsharp2v12.m4a?url&no-inline';
-import dSharp3SampleUrl from './samples/Dsharp3v12.m4a?url&no-inline';
-import dSharp4SampleUrl from './samples/Dsharp4v12.m4a?url&no-inline';
-import dSharp5SampleUrl from './samples/Dsharp5v12.m4a?url&no-inline';
-import dSharp6SampleUrl from './samples/Dsharp6v12.m4a?url&no-inline';
-import dSharp7SampleUrl from './samples/Dsharp7v12.m4a?url&no-inline';
-import fSharp1SampleUrl from './samples/Fsharp1v12.m4a?url&no-inline';
-import fSharp2SampleUrl from './samples/Fsharp2v12.m4a?url&no-inline';
-import fSharp3SampleUrl from './samples/Fsharp3v12.m4a?url&no-inline';
-import fSharp4SampleUrl from './samples/Fsharp4v12.m4a?url&no-inline';
-import fSharp5SampleUrl from './samples/Fsharp5v12.m4a?url&no-inline';
-import fSharp6SampleUrl from './samples/Fsharp6v12.m4a?url&no-inline';
-import fSharp7SampleUrl from './samples/Fsharp7v12.m4a?url&no-inline';
 
-interface PianoSampleDefinition {
+interface PianoStrikeSampleDefinition {
-  note: string;
+  kind: 'strike';
+  midi: number;
+  path: string;
+  url: string;
+  velocityLayer: number;
+}
+
+interface PianoReleaseSampleDefinition {
+  kind: 'release';
+  midi: number;
+  path: string;
   url: string;
 }
 
+type PianoSampleDefinition = PianoStrikeSampleDefinition | PianoReleaseSampleDefinition;
+
 export interface PianoSampleLoadProgress {
   failedCount: number;
   loadedCount: number;
@@ -42,54 +28,28 @@ export interface PianoSampleLoadProgress {
   totalCount: number;
 }
 
-const pianoSampleDefinitions: Array<PianoSampleDefinition> = [
+const pianoSampleModules = import.meta.glob('./samples/*.m4a', {
-  { url: a0SampleUrl, note: 'A0' },
+  eager: true,
-  { url: c1SampleUrl, note: 'C1' },
+  import: 'default',
-  { url: dSharp1SampleUrl, note: 'Dsharp1' },
+  query: '?url&no-inline',
-  { url: fSharp1SampleUrl, note: 'Fsharp1' },
+}) as Record<string, string>;
-  { url: a1SampleUrl, note: 'A1' },
+const pianoSampleDefinitions = getPianoSampleDefinitions(pianoSampleModules);
-  { url: c2SampleUrl, note: 'C2' },
-  { url: dSharp2SampleUrl, note: 'Dsharp2' },
-  { url: fSharp2SampleUrl, note: 'Fsharp2' },
-  { url: a2SampleUrl, note: 'A2' },
-  { url: c3SampleUrl, note: 'C3' },
-  { url: dSharp3SampleUrl, note: 'Dsharp3' },
-  { url: fSharp3SampleUrl, note: 'Fsharp3' },
-  { url: a3SampleUrl, note: 'A3' },
-  { url: c4SampleUrl, note: 'C4' },
-  { url: dSharp4SampleUrl, note: 'Dsharp4' },
-  { url: fSharp4SampleUrl, note: 'Fsharp4' },
-  { url: a4SampleUrl, note: 'A4' },
-  { url: c5SampleUrl, note: 'C5' },
-  { url: dSharp5SampleUrl, note: 'Dsharp5' },
-  { url: fSharp5SampleUrl, note: 'Fsharp5' },
-  { url: a5SampleUrl, note: 'A5' },
-  { url: c6SampleUrl, note: 'C6' },
-  { url: dSharp6SampleUrl, note: 'Dsharp6' },
-  { url: fSharp6SampleUrl, note: 'Fsharp6' },
-  { url: a6SampleUrl, note: 'A6' },
-  { url: c7SampleUrl, note: 'C7' },
-  { url: dSharp7SampleUrl, note: 'Dsharp7' },
-  { url: fSharp7SampleUrl, note: 'Fsharp7' },
-  { url: a7SampleUrl, note: 'A7' },
-  { url: c8SampleUrl, note: 'C8' },
-];
 
-let loadedPianoSamples: Array<LoadedPianoSample> | null = null;
+let loadedPianoSamples: LoadedPianoSamples | null = null;
-let pianoSampleLoadPromise: Promise<Array<LoadedPianoSample>> | null = null;
+let pianoSampleLoadPromise: Promise<LoadedPianoSamples> | null = null;
 let lastPianoSampleProgress: PianoSampleLoadProgress | null = null;
 const pianoSampleProgressListeners = new Set<
   (progress: PianoSampleLoadProgress) => void
 >();
 
 const sampleLoadTuning = {
-  concurrency: 4,
+  concurrency: 6,
   sampleTimeoutMs: 15_000,
 };
 
 export const preloadPianoSamples = (
   onProgress?: (progress: PianoSampleLoadProgress) => void
-): Promise<Array<LoadedPianoSample>> => {
+): Promise<LoadedPianoSamples> => {
   const OfflineAudioContextConstructor = globalThis.OfflineAudioContext;
 
   if (!OfflineAudioContextConstructor) {
@@ -106,18 +66,19 @@ export const preloadPianoSamples = (
 export const loadPianoSamples = (
   decodeContext: BaseAudioContext,
   onProgress?: (progress: PianoSampleLoadProgress) => void
-): Promise<Array<LoadedPianoSample>> => {
+): Promise<LoadedPianoSamples> => {
   const unsubscribeProgress = subscribeToPianoSampleProgress(onProgress);
 
   if (loadedPianoSamples) {
     emitPianoSampleProgress({
       failedCount: 0,
-      loadedCount: loadedPianoSamples.length,
+      loadedCount: loadedPianoSamples.strikes.length + loadedPianoSamples.releases.length,
-      settledCount: loadedPianoSamples.length,
+      settledCount:
+        loadedPianoSamples.strikes.length + loadedPianoSamples.releases.length,
       totalCount: pianoSampleDefinitions.length,
     });
     unsubscribeProgress();
-    return Promise.resolve([...loadedPianoSamples]);
+    return Promise.resolve(cloneLoadedPianoSamples(loadedPianoSamples));
   }
 
   if (pianoSampleLoadPromise) {
@@ -151,13 +112,15 @@ export const loadPianoSamples = (
   )
     .then(
       (samples) => {
-        loadedPianoSamples = samples.sort((a, b) => a.midi - b.midi);
+        loadedPianoSamples = sortLoadedPianoSamples(samples);
-        if (loadedPianoSamples.length !== pianoSampleDefinitions.length) {
+        const loadedCount =
+          loadedPianoSamples.strikes.length + loadedPianoSamples.releases.length;
+        if (loadedCount !== pianoSampleDefinitions.length) {
           throw new Error(
-            `Loaded ${loadedPianoSamples.length}/${pianoSampleDefinitions.length} piano samples.`
+            `Loaded ${loadedCount}/${pianoSampleDefinitions.length} piano samples.`
           );
         }
-        return [...loadedPianoSamples];
+        return cloneLoadedPianoSamples(loadedPianoSamples);
       },
       (error: unknown) => {
         pianoSampleLoadPromise = null;
@@ -170,29 +133,38 @@ export const loadPianoSamples = (
   return pianoSampleLoadPromise;
 };
 
-export const getLoadedPianoSamples = (): Array<LoadedPianoSample> | null =>
+export const getLoadedPianoSamples = (): LoadedPianoSamples | null =>
-  loadedPianoSamples ? [...loadedPianoSamples] : null;
+  loadedPianoSamples ? cloneLoadedPianoSamples(loadedPianoSamples) : null;
 
 const loadPianoSample = async (
   decodeContext: BaseAudioContext,
   sample: PianoSampleDefinition,
   signal: AbortSignal
-): Promise<LoadedPianoSample> => {
+): Promise<LoadedPianoStrikeSample | LoadedPianoReleaseSample> => {
   const response = await fetch(sample.url, { signal });
   if (!response.ok) {
-    throw new Error(`Unable to load piano sample ${getPianoSamplePath(sample)}`);
+    throw new Error(`Unable to load piano sample ${sample.path}`);
   }
 
   const audioData = await response.arrayBuffer();
   const buffer = await decodeContext.decodeAudioData(audioData);
-  return { midi: getMidiForPianoSample(sample), buffer };
+  if (sample.kind === 'strike') {
+    return {
+      buffer,
+      midi: sample.midi,
+      velocityLayer: sample.velocityLayer,
+    };
+  }
+  return { buffer, midi: sample.midi };
 };
 
 const loadPianoSampleBatch = async (
   samples: Array<PianoSampleDefinition>,
-  loadSample: (sample: PianoSampleDefinition) => Promise<LoadedPianoSample>
+  loadSample: (
-): Promise<Array<LoadedPianoSample>> => {
+    sample: PianoSampleDefinition
-  const results: Array<LoadedPianoSample> = [];
+  ) => Promise<LoadedPianoStrikeSample | LoadedPianoReleaseSample>
+): Promise<Array<LoadedPianoStrikeSample | LoadedPianoReleaseSample>> => {
+  const results: Array<LoadedPianoStrikeSample | LoadedPianoReleaseSample> = [];
 
   for (let index = 0; index < samples.length; index += sampleLoadTuning.concurrency) {
     const batch = samples.slice(index, index + sampleLoadTuning.concurrency);
@@ -247,13 +219,50 @@ const emitPianoSampleProgress = (progress: PianoSampleLoadProgress): void => {
   pianoSampleProgressListeners.forEach((listener) => listener(progress));
 };
 
-const getPianoSamplePath = (sample: PianoSampleDefinition): string =>
+function getPianoSampleDefinitions(
-  `./samples/${sample.note}v12.m4a`;
+  modules: Record<string, string>
+): Array<PianoSampleDefinition> {
+  return Object.entries(modules)
+    .map(([path, url]) => getPianoSampleDefinition(path, url))
+    .sort((a, b) => a.midi - b.midi || getSampleSortValue(a) - getSampleSortValue(b));
+}
 
-const getMidiForPianoSample = (sample: PianoSampleDefinition): number => {
+function getPianoSampleDefinition(path: string, url: string): PianoSampleDefinition {
-  const match = /^(?<name>[A-G])(?<accidental>sharp)?(?<octave>\d+)$/.exec(sample.note);
+  const filename = path.split('/').pop() ?? path;
+  const strikeMatch = /^(?<note>[A-G](?:sharp)?\d+)v(?<velocityLayer>\d+)\.m4a$/.exec(
+    filename
+  );
+  if (strikeMatch?.groups) {
+    return {
+      kind: 'strike',
+      midi: getMidiForPianoSampleNote(strikeMatch.groups.note),
+      path,
+      url,
+      velocityLayer: Number(strikeMatch.groups.velocityLayer),
+    };
+  }
+
+  const releaseMatch = /^rel(?<releaseIndex>\d+)\.m4a$/.exec(filename);
+  if (releaseMatch?.groups) {
+    return {
+      kind: 'release',
+      midi: getMidiForReleaseSample(Number(releaseMatch.groups.releaseIndex)),
+      path,
+      url,
+    };
+  }
+
+  throw new Error(`Invalid piano sample filename ${path}`);
+}
+
+function getSampleSortValue(sample: PianoSampleDefinition): number {
+  return sample.kind === 'strike' ? sample.velocityLayer : Number.MAX_SAFE_INTEGER;
+}
+
+function getMidiForPianoSampleNote(note: string): number {
+  const match = /^(?<name>[A-G])(?<accidental>sharp)?(?<octave>\d+)$/.exec(note);
   if (!match?.groups) {
-    throw new Error(`Invalid piano sample note ${sample.note}`);
+    throw new Error(`Invalid piano sample note ${note}`);
   }
 
   const semitoneByName: Record<string, number> = {
@@ -268,4 +277,25 @@ const getMidiForPianoSample = (sample: PianoSampleDefinition): number => {
   const octave = Number(match.groups.octave);
   const semitone = semitoneByName[match.groups.name] + (match.groups.accidental ? 1 : 0);
   return (octave + 1) * 12 + semitone;
-};
+}
+
+function getMidiForReleaseSample(releaseIndex: number): number {
+  const pianoLowestMidi = 21;
+  return pianoLowestMidi + releaseIndex - 1;
+}
+
+const sortLoadedPianoSamples = (
+  samples: Array<LoadedPianoStrikeSample | LoadedPianoReleaseSample>
+): LoadedPianoSamples => ({
+  releases: samples
+    .filter((sample): sample is LoadedPianoReleaseSample => !('velocityLayer' in sample))
+    .sort((a, b) => a.midi - b.midi),
+  strikes: samples
+    .filter((sample): sample is LoadedPianoStrikeSample => 'velocityLayer' in sample)
+    .sort((a, b) => a.midi - b.midi || a.velocityLayer - b.velocityLayer),
+});
+
+const cloneLoadedPianoSamples = (samples: LoadedPianoSamples): LoadedPianoSamples => ({
+  releases: [...samples.releases],
+  strikes: [...samples.strikes],
+});