String Pluck JS

A dependency-free browser instrument built with the Web Audio API. string-pluck.js implements a Karplus–Strong plucked string; index.html is a responsive, playable demo.

Try it

Put index.html and string-pluck.js in the same folder and open index.html in a modern browser. Click a string or press 1–6; press Space to strum. Audio starts after a user interaction, as browsers require.

Use it in a page

<script src="string-pluck.js"></script>
<button id="play">Pluck A</button>
<script>
  const stringPluck = new StringPluck({ decay: 2.4, brightness: 0.7 });
  document.querySelector('#play').addEventListener('click', async () => {
    await stringPluck.resume();
    stringPluck.pluck(110); // A2, 110 Hz
  });
</script>

new StringPluck({ context?, destination?, attack?, decay?, brightness?, damping?, pickPosition?, volume? }) accepts an optional existing AudioContext and destination node. pluck(frequency, velocity = 1, overrides = {}) plays a note and returns its voice; setParams({...}) updates subsequent plucks; stopAll() silences active voices; dispose() releases nodes and closes the context only if the plugin created it. Values are clamped to safe ranges. Frequency must be 40–2000 Hz.

Parameter	Range	Default	Effect
attack	0.001–0.5 s	0.008	Fade-in time
decay	0.15–8 s	2.2	Approximate sustain length
brightness	0–1	0.65	Excitation noise and low-pass cutoff
damping	0–1	0.28	High-frequency loss in the feedback loop
pickPosition	0.05–0.5	0.22	Pluck location along the string
volume	0–1	0.7	Note level

The plugin generates a short buffer for every pluck. It is suited to interactive demos and modest polyphony; very long decays and heavy polyphony increase CPU and memory use. This synthesizes a string rather than using guitar samples, so it does not model a guitar body, fret noise, or realistic articulation.