0.12.0 • Public • Published

    soundfont-player npm

    Build Status js-standard-style license

    A soundfont loader/player to play MIDI sounds using WebAudio API.

    It loads Benjamin Gleitzman's package of pre-rendered sound fonts by default with no server setup. Just a few lines of javascript:

    Soundfont.instrument(new AudioContext(), 'acoustic_grand_piano').then(function (piano) {'C4')

    It is a much simpler and lightweight replacement for MIDI.js soundfont loader (MIDI.js is much bigger, capable of play midi files, for example, but it weights an order of magnitude more).


    • Load soundfont files in MIDI.js format or json format.
    • Unlimited poliphony (and stop all sounds with a single function call)
    • Use midi note numbers. Accepts decimal points to detune.
    • Easily connect to a Web MIDI API MidiInput
    • Schedule a list of notes

    It uses audio-loader to load soundfont files and sample-player to play the sounds.


    Via npm: npm install --save soundfont-player

    Or download the minified code and include it in your html:

    <script src="soundfont-player.js"></script>
      Soundfont.instrument(new AudioContext(), 'marimba').then(function (marimba) {


    The soundfont loader

    Out of the box are two Soundfonts available: MusyngKite and FluidR3_GM (MusyngKite by default: has more quality, but also weights more). You can load them with instrument function:

    Soundfont.instrument(ac, 'clavinet').then(function (clavinet) {'C4')
    // or use FluidR3_GM
    Soundfont.instrument(ac, 'clavinet', { soundfont: 'FluidR3_GM' }).then(function (clavinet) {'C4')

    You can load your own Soundfont files passing the .js path or url:

    Soundfont.instrument(ac, '/soundfonts/clavinet-mp3.js').then(...)
    // or
    Soundfont.instrument(ac, 'clavinet-mp3.js', { from: '' })

    The soundfont player

    Once you have an instrument you can:

    // The first step is always create an instrument:
    Soundfont.instrument(ac, 'clavinet').then(function (clavinet) {
      // Then you can play a note using names or midi numbers:'C4')
      // float point midi numbers are accepted (and notes are detuned): // => 500 cents over C4
      // you can stop all playing notes
      // or stop only one'C4').stop(ac.currentTime + 0.5)
      // or pass a duration argument to `play`'C4', ac.currentTime, { duration: 0.5})
      // You can connect the instrument to a midi input:
      window.navigator.requestMIDIAccess().then(function (midiAccess) {
        midiAccess.inputs.forEach(function (midiInput) {
      // Or schedule events at a given time
      clavinet.schedule(ac.currentTime + 5, [ { time: 0, note: 60}, { time: 0.5, note: 61}, ...])


    < 0.9.x users: The API in the 0.9.x releases has been changed and some features are going to be removed (like oscillators). While 0.9.0 adds warnings to the deprecated API, the 1.0.0 will remove the support.

    instrument(ac, name, options) ⇒ Promise

    Load a soundfont instrument. It returns a promise that resolves to a instrument object.

    The instrument object returned by the promise has the following properties:

    • name: the instrument name
    • play: A function to play notes from the buffer with the signature play(note, time, duration, options)

    The valid options are:

    • format: can be 'mp3' or 'ogg'
    • soundfont: can be 'FluidR3_GM' or 'MusyngKite'
    • nameToUrl: a function to convert from instrument names to URL
    • destination: by default Soundfont uses the audioContext.destination but you can override it.
    • gain: the gain (volume) of the player (1 by default)
    • attack: the attack time of the amplitude envelope
    • decay: the decay time of the amplitude envelope
    • sustain: the sustain gain value of the amplitude envelope
    • release: the release time of the amplitude envelope
    • adsr: the amplitude envelope as array of [attack, decay, sustain, release]. It overrides other options.
    • loop: set to true to loop audio buffers
    • notes: an array of the notes to decode. It can be an array of strings with note names or an array of numbers with midi note numbers. This is a performance option: since decoding mp3 is a cpu intensive process, you can limit limit the number of notes you want and reduce the time to load the instrument.
    Param Type Description
    ac AudioContext the audio context
    name String the instrument name. For example: 'acoustic_grand_piano'
    options Object (Optional) the same options as Soundfont.loadBuffers


    var Soundfont = require('sounfont-player')
    var ac = new AudioContext()
    Soundfont.instrument(ac, 'marimba', { soundfont: 'MusyngKite' }).then(function (marimba) {'C4')

    The player

    The player object returned by the promise has the following functions:

    An alias for player.start

    player.start(name, when, options) ⇒ AudioNode

    Start a sample buffer. The returned object has a function stop(when) to stop the sound.

    Valid options are:

    • gain: float between 0 to 1
    • attack: the attack time of the amplitude envelope
    • decay: the decay time of the amplitude envelope
    • sustain: the sustain gain value of the amplitude envelope
    • release: the release time of the amplitude envelope
    • adsr: an array of [attack, decay, sustain, release]. Overrides other parameters.
    • duration: set the playing duration in seconds of the buffer(s)
    • loop: set to true to loop the audio buffer

    player.stop(when, nodes) ⇒ Array

    Stop some or all samples

    player.on(event, callback) ⇒ player

    Adds a listener of an event

    player.connect(destination) ⇒ AudioPlayer

    Connect the player to a destination node

    player.schedule(when, events) ⇒ Array

    Schedule a list of events to be played at specific time.

    player.listenToMidi(input, options) ⇒ player

    Connect a player to a midi input

    See soundfont-player for more information.

    nameToUrl(name, soundfont, format) ⇒ String

    Given an instrument name returns a URL to to the Benjamin Gleitzman's package of pre-rendered sound fonts

    Returns: String - the Soundfont file url

    Param Type Description
    name String instrument name
    soundfont String (Optional) 'FluidR3_GM' or 'MusyngKite' ('MusyngKite' by default)
    format String (Optional) Can be 'mp3' or 'ogg' (mp3 by default)


    var Soundfont = require('soundfont-player')
    Soundfont.nameToUrl('marimba', null, 'ogg') // =>

    Run the tests, examples and build the library distribution file

    First clone this repo and install dependencies: npm i

    To run tests use npm: npm test

    The dist folder contains ready to use file for browser. You can use the dist file from the repo, but if you want to build you own run: npm run dist

    To run the html example start a local http server. For example:

    npm install -g http-server

    And open http://localhost:8080/examples

    To run pure javascript examples npm install -g beefy then beefy examples/marimba.js and navigate to http://localhost:9966/

    Available instruments

    By default it loads Benjamin Gleitzman's pre-rendered SoundFonts.

    Instrument names

    You can download the names of the instruments as a .json file:

    Or require them:

    var fluidNames = require('soundfont-player/names/fuildR3.json')
    var musyngNames = require('soundfont-player/names/musyngkite.json')



    MIT License


    npm i soundfont-player

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    • danigb