text: var low = 60;
  var high = 84;
  var piano = new SVGIntPiano("cont",{
    lowNote: low,
    highNote: high
  });
  
  var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
  var gain = audioCtx.createGain();
  gain.connect(audioCtx.destination);
  gain.gain.value = 0.1;
  
  var midicps = (midi)=>{
    return 440*Math.pow(2, (midi-69)/12);
  };
  
  var oscs = {};
  
  piano.subscribe("keyon", (mn)=>{
    oscs[mn] = audioCtx.createOscillator();
    oscs[mn].connect(gain);
    oscs[mn].type = 'sine';
    oscs[mn].frequency.value = midicps(mn);
    oscs[mn].start();
  });
  
  piano.subscribe("keyoff", (mn)=>{
    oscs[mn].stop();
  })
  