Xylophone

Simple library for creating tones using the WebAudioAPI

Installation

npm install xylophone --save

or

Download xylophone.js from master and include it in your project

<script src="./path/to/xylophone.js"></script>

Example

import Xylophone from 'xylophone'

const xylophone = new Xylophone()

// Play one measure
await xylophone.play({
  notes: ['C4', 'E4', 'C4', 'E4'],
  length: 0.5,
  offset: 0.25
})

// Play an array of measures
await xylophone.play([
  {
    notes: ['C4', 'E4', 'C4', 'E4'],
    length: 0.5,
    offset: 0.25
  },
  {
    notes: ['C4', 'G4', 'A3'],
    length: 0.3,
    offset: 0.25
  },
  {
    notes: ['C4', 'B3', 'Bb3', 'A#3', 'A3'],
    length: 0.5,
    offset: 0.25
  }
])

// Create a loop
const cancel = await xylophone.loop([
  {
    notes: ['C4', 'E4', 'C4', 'E4'],
    length: 0.5,
    offset: 0.25,
    type: 'square'
  },
  {
    notes: ['C4', 'G4', 'A3'],
    length: 0.3,
    offset: 0.25,
    type: 'triangle'
  },
  {
    notes: ['C4', 'B3', 'Bb3', 'A#3', 'A3'],
    length: 0.5,
    offset: 0.25,
    type: 'sawtooth'
  }
])

// Stop the loop in 20 seconds
setTimeout(cancel, 20000)

Usage

interface IMeasure

notes: string[] // 'C0' through 'C8' on the equal tempered scale
length?: number // The length of each note
offset?: number // The offset between notes (e.i. `offset: 0` would play all the notes at the same time)
type?: "sine" | "square" | "sawtooth" | "triangle"

equal tempered scale?

Xylophone.prototype.play(measure: IMeasure | IMeasure[]): Promise<void>

Plays a series of notes in an IMeasure. If an array of IMeasures is given then each IMeasure will play when the previous one ends.

• Resolves when all sound has stopped.

Xylophone.prototype.loop(measure: IMeasure | IMeasure[]): Promise<() => void)>

Plays measure in a loop until canceled.

• returns cancel() => void Canceles the loop when called

Support

Xylophone supports any browser with AudioContext or webkitAudioContext support
See caniuse.com for details

License

MIT