Chord React component that plays a combination of 3 oscillators to generate a Chord

chord.js

// A Chord react (or call it preact) component that plays a combination of 3 oscillators
// And generates various chords
// <Chord chordname="C Major" frequencies="196.00, 261.63, 329.63" type="sine" />

import { h, Component } from 'preact';
import style from './style';

const audioContext = new (window.AudioContext || window.webkitAudioContext);

export default class Chord extends Component {

  play() {
    if( this.oscillators ) return;
    this.oscillators = [];
    var THIS = this;
    this.props.frequencies.split(",").forEach(function(item, index){
      var oscillator = audioContext.createOscillator();
      oscillator.type = THIS.props.type || 'sine';
      oscillator.frequency.value = (item * 1) || 329.63; //E(1) is default
      oscillator.connect(audioContext.destination);
      oscillator.start(); 
      THIS.oscillators.push( oscillator );
    });
  }

  stop() {
    if(!this.oscillators) return;
    this.oscillators.forEach(function(oscillator, index){
      oscillator.stop();
      oscillator = null;
    });
    this.oscillators = null;
  }

  render() {
    return (
      <div>
        <table class={style.w_70}>
          <tr>
            <td>
              <strong>{this.props.chordname}</strong>
            </td>
            <td>{this.props.frequencies}</td>
            <td>
              <button onClick={this.play.bind(this)}>start</button>
              &nbsp; &nbsp;
              <button onClick={this.stop.bind(this)}>stop</button>
            </td>
          </tr>
        </table>
      </div>
    );
  }
}