src/components/Music.ts

@@ -8,15 +8,23 @@ import type { Sequence } from '../core/Music.ts';
 export class Music extends Component {
   sequences: Map<string, Sequence>;
   currentSequence: Sequence | null;
+  activeSequences: Set<Sequence>;
   volume: number;
   enabled: boolean;
+  private sequenceChain: string[];
+  private currentChainIndex: number;
+  private sequenceVolumes: Map<Sequence, number>;
 
   constructor() {
     super(ComponentType.MUSIC);
     this.sequences = new Map();
     this.currentSequence = null;
+    this.activeSequences = new Set();
     this.volume = 0.5;
     this.enabled = true;
+    this.sequenceChain = [];
+    this.currentChainIndex = 0;
+    this.sequenceVolumes = new Map();
   }
 
   /**
@@ -49,10 +57,91 @@ export class Music extends Component {
     }
   }
 
+  /**
+   * Play multiple sequences simultaneously (polyphony).
+   * @param sequenceConfigs - Array of configs with name, optional delay in beats, and optional loop
+   */
+  playSequences(sequenceConfigs: Array<{ name: string; delay?: number; loop?: boolean }>): void {
+    if (!this.enabled || sequenceConfigs.length === 0) return;
+
+    const firstSeq = this.sequences.get(sequenceConfigs[0].name);
+    if (!firstSeq || !firstSeq.ac) return;
+
+    const ac = firstSeq.ac;
+    const when = ac.currentTime;
+    const tempo = firstSeq.tempo || 120;
+
+    sequenceConfigs.forEach((config) => {
+      const sequence = this.sequences.get(config.name);
+      if (!sequence) return;
+
+      if (config.loop !== undefined) {
+        sequence.loop = config.loop;
+      }
+      if (sequence.gain) {
+        sequence.gain.gain.value = this.volume;
+      }
+
+      const delaySeconds = config.delay ? (60 / tempo) * config.delay : 0;
+      sequence.play(when + delaySeconds);
+      this.activeSequences.add(sequence);
+
+      if (!this.currentSequence) {
+        this.currentSequence = sequence;
+      }
+    });
+  }
+
+  /**
+   * Chain multiple sequences together in order (sequential playback).
+   * @param sequenceNames - Array of sequence names to play in order
+   */
+  chainSequences(sequenceNames: string[]): void {
+    if (!this.enabled || sequenceNames.length === 0) return;
+
+    this.stop();
+    this.sequenceChain = sequenceNames;
+    this.currentChainIndex = 0;
+
+    this.playNextInChain();
+  }
+
+  /**
+   * Play the next sequence in the chain.
+   */
+  private playNextInChain(): void {
+    if (!this.enabled || this.sequenceChain.length === 0) return;
+
+    const seqName = this.sequenceChain[this.currentChainIndex];
+    const sequence = this.sequences.get(seqName);
+    if (!sequence) return;
+
+    this.currentSequence = sequence;
+    sequence.loop = false;
+    if (sequence.gain) {
+      sequence.gain.gain.value = this.volume;
+    }
+
+    sequence.play();
+    if (sequence.osc) {
+      const nextIndex = (this.currentChainIndex + 1) % this.sequenceChain.length;
+      sequence.osc.onended = () => {
+        if (this.enabled) {
+          this.currentChainIndex = nextIndex;
+          this.playNextInChain();
+        }
+      };
+    }
+  }
+
   /**
    * Stop current playback.
    */
   stop(): void {
+    this.activeSequences.forEach((seq) => {
+      seq.stop();
+    });
+    this.activeSequences.clear();
     if (this.currentSequence) {
       this.currentSequence.stop();
       this.currentSequence = null;
@@ -85,4 +174,61 @@ export class Music extends Component {
       this.stop();
     }
   }
+
+  /**
+   * Pause all active sequences by setting their gain to 0.
+   */
+  pause(): void {
+    this.activeSequences.forEach((seq) => {
+      if (seq.gain) {
+        const currentVolume = seq.gain.gain.value;
+        this.sequenceVolumes.set(seq, currentVolume);
+        seq.gain.gain.value = 0;
+      }
+    });
+    if (this.currentSequence && this.currentSequence.gain) {
+      const currentVolume = this.currentSequence.gain.gain.value;
+      this.sequenceVolumes.set(this.currentSequence, currentVolume);
+      this.currentSequence.gain.gain.value = 0;
+    }
+    this.sequences.forEach((seq) => {
+      if (seq.gain && seq.gain.gain.value > 0) {
+        const currentVolume = seq.gain.gain.value;
+        this.sequenceVolumes.set(seq, currentVolume);
+        seq.gain.gain.value = 0;
+      }
+    });
+  }
+
+  /**
+   * Resume all active sequences by restoring their volume.
+   */
+  resume(): void {
+    this.activeSequences.forEach((seq) => {
+      if (seq.gain) {
+        const savedVolume = this.sequenceVolumes.get(seq);
+        if (savedVolume !== undefined) {
+          seq.gain.gain.value = savedVolume;
+        } else {
+          seq.gain.gain.value = this.volume;
+        }
+      }
+    });
+    if (this.currentSequence && this.currentSequence.gain) {
+      const savedVolume = this.sequenceVolumes.get(this.currentSequence);
+      if (savedVolume !== undefined) {
+        this.currentSequence.gain.gain.value = savedVolume;
+      } else {
+        this.currentSequence.gain.gain.value = this.volume;
+      }
+    }
+    this.sequences.forEach((seq) => {
+      if (seq.gain) {
+        const savedVolume = this.sequenceVolumes.get(seq);
+        if (savedVolume !== undefined) {
+          seq.gain.gain.value = savedVolume;
+        }
+      }
+    });
+  }
 }

src/config/MusicConfig.ts

@@ -0,0 +1,167 @@
+import { Sequence } from '../core/Music.ts';
+import type { Music } from '../components/Music.ts';
+import type { MusicSystem } from '../systems/MusicSystem.ts';
+
+/**
+ * Configure and setup background music.
+ * @param music - Music component instance
+ * @param audioCtx - AudioContext instance
+ */
+export function setupMusic(music: Music, audioCtx: AudioContext): void {
+  const tempo = 132;
+
+  const lead = new Sequence(audioCtx, tempo, [
+    'F4 e',
+    'Ab4 e',
+    'C5 e',
+    'F5 e',
+    'C5 e',
+    'Ab4 e',
+    'F4 e',
+    'C4 e',
+    'F4 e',
+    'Ab4 e',
+    'C5 e',
+    'F5 e',
+    'C5 e',
+    'Ab4 e',
+    'F4 e',
+    'C4 e',
+    'G4 e',
+    'Bb4 e',
+    'D5 e',
+    'G5 e',
+    'D5 e',
+    'Bb4 e',
+    'G4 e',
+    'D4 e',
+    'F4 e',
+    'Ab4 e',
+    'C5 e',
+    'F5 e',
+    'C5 e',
+    'Ab4 e',
+    'F4 e',
+    'C4 e',
+  ]);
+  lead.staccato = 0.1;
+  lead.smoothing = 0.3;
+  lead.waveType = 'triangle';
+  lead.loop = true;
+  if (lead.gain) {
+    lead.gain.gain.value = 0.8;
+  }
+  music.addSequence('lead', lead);
+
+  const harmony = new Sequence(audioCtx, tempo, [
+    'C4 e',
+    'Eb4 e',
+    'F4 e',
+    'Ab4 e',
+    'F4 e',
+    'Eb4 e',
+    'C4 e',
+    'Ab3 e',
+    'C4 e',
+    'Eb4 e',
+    'F4 e',
+    'Ab4 e',
+    'F4 e',
+    'Eb4 e',
+    'C4 e',
+    'Ab3 e',
+    'D4 e',
+    'F4 e',
+    'G4 e',
+    'Bb4 e',
+    'G4 e',
+    'F4 e',
+    'D4 e',
+    'Bb3 e',
+    'C4 e',
+    'Eb4 e',
+    'F4 e',
+    'Ab4 e',
+    'F4 e',
+    'Eb4 e',
+    'C4 e',
+    'Ab3 e',
+  ]);
+  harmony.staccato = 0.15;
+  harmony.smoothing = 0.4;
+  harmony.waveType = 'triangle';
+  harmony.loop = true;
+  if (harmony.gain) {
+    harmony.gain.gain.value = 0.6;
+  }
+  music.addSequence('harmony', harmony);
+
+  const bass = new Sequence(audioCtx, tempo, [
+    'F2 q',
+    'C3 q',
+    'F2 q',
+    'C3 q',
+    'G2 q',
+    'D3 q',
+    'G2 q',
+    'D3 q',
+    'F2 q',
+    'C3 q',
+    'F2 q',
+    'C3 q',
+  ]);
+  bass.staccato = 0.05;
+  bass.smoothing = 0.5;
+  bass.waveType = 'triangle';
+  bass.loop = true;
+  if (bass.gain) {
+    bass.gain.gain.value = 0.7;
+  }
+  if (bass.bass) {
+    bass.bass.gain.value = 4;
+    bass.bass.frequency.value = 80;
+  }
+  music.addSequence('bass', bass);
+
+  music.playSequences([
+    { name: 'lead', loop: true },
+    { name: 'harmony', loop: true },
+    { name: 'bass', loop: true },
+  ]);
+  music.setVolume(0.02);
+}
+
+/**
+ * Setup music event handlers for canvas interaction.
+ * @param music - Music component instance
+ * @param musicSystem - MusicSystem instance
+ * @param canvas - Canvas element
+ */
+export function setupMusicHandlers(
+  music: Music,
+  musicSystem: MusicSystem,
+  canvas: HTMLCanvasElement
+): void {
+  canvas.addEventListener('click', () => {
+    musicSystem.resumeAudioContext();
+    if (music.enabled && music.activeSequences.size === 0) {
+      music.playSequences([
+        { name: 'lead', loop: true },
+        { name: 'harmony', loop: true },
+        { name: 'bass', loop: true },
+      ]);
+    }
+    canvas.focus();
+  });
+
+  setTimeout(() => {
+    musicSystem.resumeAudioContext();
+    if (music.enabled) {
+      music.playSequences([
+        { name: 'lead', loop: true },
+        { name: 'harmony', loop: true },
+        { name: 'bass', loop: true },
+      ]);
+    }
+  }, 1000);
+}

src/config/SFXConfig.ts

@@ -0,0 +1,35 @@
+import { Sequence } from '../core/Music.ts';
+import type { SoundEffects } from '../components/SoundEffects.ts';
+
+/**
+ * Configure and setup sound effects.
+ * @param sfx - SoundEffects component instance
+ * @param ac - AudioContext instance
+ */
+export function setupSFX(sfx: SoundEffects, ac: AudioContext): void {
+  const attackSound = new Sequence(ac, 120, ['C5 s']);
+  attackSound.staccato = 0.8;
+  sfx.addSound('attack', attackSound);
+
+  const absorbSound = new Sequence(ac, 120, ['G4 e']);
+  absorbSound.staccato = 0.5;
+  sfx.addSound('absorb', absorbSound);
+
+  const skillSound = new Sequence(ac, 120, ['A4 e']);
+  skillSound.staccato = 0.6;
+  sfx.addSound('skill', skillSound);
+
+  const damageSound = new Sequence(ac, 120, ['F4 s']);
+  damageSound.staccato = 0.8;
+  sfx.addSound('damage', damageSound);
+
+  const shootSound = new Sequence(ac, 120, ['C5 s']);
+  shootSound.staccato = 0.9;
+  sfx.addSound('shoot', shootSound);
+
+  const impactSound = new Sequence(ac, 120, ['G4 s']);
+  impactSound.staccato = 0.7;
+  sfx.addSound('impact', impactSound);
+
+  sfx.setVolume(0.02);
+}

src/core/Engine.ts

@@ -143,7 +143,7 @@ export class Engine {
       | undefined;
     const gameState = menuSystem ? menuSystem.getGameState() : GameState.PLAYING;
     const isPaused = [GameState.PAUSED, GameState.START, GameState.GAME_OVER].includes(gameState);
-    const unskippedSystems = [SystemName.MENU, SystemName.UI, SystemName.RENDER];
+    const unskippedSystems = [SystemName.MENU, SystemName.UI, SystemName.RENDER, SystemName.MUSIC];
 
     this.systems.forEach((system) => {
       if (isPaused && !unskippedSystems.includes(system.name as SystemName)) {

src/main.ts

@@ -36,8 +36,9 @@ import { Music } from './components/Music.ts';
 import { SoundEffects } from './components/SoundEffects.ts';
 
 import { EntityType, ComponentType } from './core/Constants.ts';
-import { Sequence } from './core/Music.ts';
 import type { Entity } from './core/Entity.ts';
+import { setupMusic, setupMusicHandlers } from './config/MusicConfig.ts';
+import { setupSFX } from './config/SFXConfig.ts';
 
 const canvas = document.getElementById('game-canvas') as HTMLCanvasElement;
 if (!canvas) {
@@ -156,90 +157,19 @@ if (!canvas) {
   if (musicSystem) {
     const musicEntity = engine.createEntity();
     const music = new Music();
-    const ac = musicSystem.getAudioContext();
+    const audioCtx = musicSystem.getAudioContext();
 
-    const bgMusic = new Sequence(ac, 140, [
-      'C4 e',
-      'E4 e',
-      'G4 q',
-      'C5 e',
-      'G4 e',
-      'E4 q',
-      'A3 e',
-      'C4 e',
-      'E4 q',
-      'A4 e',
-      'E4 e',
-      'C4 q',
-      'F3 e',
-      'A3 e',
-      'C4 q',
-      'F4 e',
-      'C4 e',
-      'A3 q',
-      'G3 e',
-      'B3 e',
-      'D4 q',
-      'G4 e',
-      'D4 e',
-      'B3 q',
-    ]);
-    bgMusic.loop = true;
-    bgMusic.staccato = 0.2;
-    bgMusic.smoothing = 0.4;
-    bgMusic.waveType = 'triangle';
-    music.addSequence('background', bgMusic);
-    music.setVolume(0.02);
+    setupMusic(music, audioCtx);
     musicEntity.addComponent(music);
-
-    canvas.addEventListener('click', () => {
-      musicSystem.resumeAudioContext();
-      if (music.enabled && !music.currentSequence) {
-        music.playSequence('background');
-      }
-      canvas.focus();
-    });
-
-    setTimeout(() => {
-      musicSystem.resumeAudioContext();
-      if (music.enabled) {
-        music.playSequence('background');
-      }
-    }, 1000);
+    setupMusicHandlers(music, musicSystem, canvas);
 
     const sfxSystem = engine.systems.find((s) => s.name === 'SoundEffectsSystem') as
       | SoundEffectsSystem
       | undefined;
     if (sfxSystem) {
       const sfxEntity = engine.createEntity();
-      const sfx = new SoundEffects(ac);
-
-      const attackSound = new Sequence(ac, 120, ['C5 s']);
-      attackSound.staccato = 0.8;
-      sfx.addSound('attack', attackSound);
-
-      const absorbSound = new Sequence(ac, 120, ['G4 e']);
-      absorbSound.staccato = 0.5;
-      sfx.addSound('absorb', absorbSound);
-
-      const skillSound = new Sequence(ac, 120, ['A4 e']);
-      skillSound.staccato = 0.6;
-      sfx.addSound('skill', skillSound);
-
-      const damageSound = new Sequence(ac, 120, ['F4 s']);
-      damageSound.staccato = 0.8;
-      sfx.addSound('damage', damageSound);
-
-      const shootSound = new Sequence(ac, 120, ['C5 s']);
-      shootSound.staccato = 0.9;
-      sfx.addSound('shoot', shootSound);
-
-      const impactSound = new Sequence(ac, 120, ['G4 s']);
-      impactSound.staccato = 0.7;
-      sfx.addSound('impact', impactSound);
-
-      sfx.setVolume(0.02);
-
+      const sfx = new SoundEffects(audioCtx);
+      setupSFX(sfx, audioCtx);
       sfxEntity.addComponent(sfx);
     }
   } else {

src/systems/MusicSystem.ts

@@ -1,20 +1,23 @@
 import { System } from '../core/System.ts';
-import { SystemName, ComponentType } from '../core/Constants.ts';
+import { SystemName, ComponentType, GameState } from '../core/Constants.ts';
 import type { Entity } from '../core/Entity.ts';
 import type { Engine } from '../core/Engine.ts';
 import type { Music } from '../components/Music.ts';
+import type { MenuSystem } from './MenuSystem.ts';
 
 /**
  * System responsible for managing background music playback.
  */
 export class MusicSystem extends System {
   private audioContext: AudioContext | null;
+  private wasPaused: boolean;
 
   constructor() {
     super(SystemName.MUSIC);
     this.requiredComponents = [ComponentType.MUSIC];
     this.priority = 5;
     this.audioContext = null;
+    this.wasPaused = false;
   }
 
   /**
@@ -25,9 +28,15 @@ export class MusicSystem extends System {
   }
 
   /**
-   * Process music entities - currently just ensures audio context exists.
+   * Process music entities - ensures audio context exists and handles pause/resume.
    */
   process(_deltaTime: number, entities: Entity[]): void {
+    const menuSystem = this.engine.systems.find((s) => s.name === SystemName.MENU) as
+      | MenuSystem
+      | undefined;
+    const gameState = menuSystem ? menuSystem.getGameState() : GameState.PLAYING;
+    const isPaused = gameState === GameState.PAUSED;
+
     entities.forEach((entity) => {
       const music = entity.getComponent<Music>(ComponentType.MUSIC);
       if (!music) return;
@@ -35,6 +44,14 @@ export class MusicSystem extends System {
       if (!this.audioContext) {
         this.audioContext = new AudioContext();
       }
+
+      if (isPaused && !this.wasPaused) {
+        music.pause();
+        this.wasPaused = true;
+      } else if (!isPaused && this.wasPaused) {
+        music.resume();
+        this.wasPaused = false;
+      }
     });
   }