Tone.js wraps the low-level Web Audio API with musician-friendly constructs (Synth, Sampler, Transport), giving you DAW-like power in the browser

// play a middle-C for an 8th-note
import * as Tone from "tone";
const synth = new Tone.Synth().toDestination();
await Tone.start();          // user-gesture gate
synth.triggerAttackRelease("C4","8n");

1. NPM / Yarn

   npm install tone            # latest stable
   npm install tone@next       # bleeding edge

2. ESM import

   import * as Tone from "tone";

3. UNPKG CDN

   <script src="https://unpkg.com/tone"></script>

👉 Remember to call Tone.start() after a user event before making sound

3.1 Transport & Timed Events

The Tone.getTransport() clock synchronises every scheduled callback. Start, stop, loop, change tempo, and quantise events reliably

// quarter-note loop on C2
const synth = new Tone.FMSynth().toDestination();
const loop = new Tone.Loop((time)=>{
    synth.triggerAttackRelease("C2","8n",time);
},"4n").start(0);
Tone.getTransport().bpm.value = 120;
Tone.getTransport().start();

3.2 Mono & Poly Synths

Create basses, leads or poly pads instantly with built-ins like Synth, FMSynth, and PolySynth.

3.3 Samples & Players

Load single shots via Player, or multi-sample instruments with Sampler—complete with pitch-shifting

3.4 Effects & Routing

Insert or parallel-route any number of effects (Delay, Reverb, Distortion). Patch nodes exactly like physical cables.

// serial effect chain
const player = new Tone.Player("loop.mp3").start();
const delay  = new Tone.FeedbackDelay("8n",0.4).toDestination();
player.connect(delay);

1. Latency Hints — pass { latencyHint:"playback" } to minimise glitching on mobile.

2. AudioWorklet Support — v14.7 introduced direct AudioWorkletNode constructors for DSP in a worker

3. Custom Param Interpolations — drive any Signal with ramps, curves, or external LFOs.

// Basic Web-MIDI → Tone synth
if (navigator.requestMIDIAccess){
  const synth = new Tone.PolySynth(Tone.Synth).toDestination();
  navigator.requestMIDIAccess().then(access=>{
    access.inputs.forEach(inp=>{
      inp.onmidimessage = e=>{
        const [cmd,note,vel] = e.data;
        if (cmd===144 && vel>0)     synth.triggerAttack(Tone.Frequency(note,"midi"));
        if (cmd===128 || vel===0)   synth.triggerRelease(Tone.Frequency(note,"midi"));
      }
    });
  });
}

Use Tone.Recorder for live capture, or Tone.Offline to render faster-than-real-time for glitch-free bounces.

// live record
const rec = new Tone.Recorder();
synth.connect(rec);
await rec.start();
await Tone.start();
synth.triggerAttackRelease("C4","2n");
const wav = await rec.stop();
download(wav,"take-1.wav");

1. Batch sample loads with Tone.loaded().

2. Dispose unused nodes via .dispose() to free memory.

3. Query Tone.context.baseLatency to adapt buffer sizes per device.

Feature	Notes
Typescript Migration	Entire codebase now ships with .d.ts for intellisense
AudioWorklet Support	Real-time DSP off the main thread
Destination rename	Master ➜ Destination for clarity
Param Improvements	Signals are simpler (SyncedSignal) and more powerful.

1. Official Docs & API Reference.

2. GitHub Releases.

3. Interactive Examples.