Play it again JavaScript

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>
  <button class='button1' onmousedown='noise(261.63)'onmouseup='silence()' >C</button>
  <button class='button2' onmousedown='noise(293.66)'onmouseup='silence()' >D</button>
  <button class='button1' onmousedown='noise(329.63)'onmouseup='silence()' >E</button>
  <button class='button2' onmousedown='noise(349.23)'onmouseup='silence()' >F</button>
  <button class='button1' onmousedown='noise(392.00)'onmouseup='silence()' >G</button>
  <button class='button1' onmousedown='noise(440.00)'onmouseup='silence()' >A</button>
  <button class='button2' onmousedown='noise(493.88)'onmouseup='silence()' >B</button>
<script id="jsbin-javascript">
var AudioContext = window.AudioContext || window.webkitAudioContext;
var audioCtx = new AudioContext();

var oscillator = audioCtx.createOscillator();
var gainNode = audioCtx.createGain();
var finish = audioCtx.destination;

oscillator.type = 'square';
oscillator.start();

function noise(value){
  oscillator.frequency.value = value; // value in hertz
  oscillator.connect(audioCtx.destination);
  
}

function silence(){
  oscillator.disconnect(audioCtx.destination);
}
</script>

var oscillator = audioCtx.createOscillator();
var gainNode = audioCtx.createGain();
var finish = audioCtx.destination;

oscillator.type = 'square';
oscillator.start();

function noise(value){
  oscillator.frequency.value = value; // value in hertz
  oscillator.connect(audioCtx.destination);
  
}

function silence(){
  oscillator.disconnect(audioCtx.destination);
}

</script></body>
</html>