JS Web Audio API Synth Based On Movement W/ Canvas Spray Can

<script>
var audioCtx=new AudioContext();
var oscillator = audioCtx.createOscillator();
var gainNode = audioCtx.createGain();
oscillator.connect(gainNode);
gainNode.connect(audioCtx.destination);
var WIDTH = window.innerWidth;
var HEIGHT = window.innerHeight;
var FreqMax = 2000;
var VolMax = 1;
var Freq = 1000;
var Vol = 0.1;
oscillator.type = 'sawtooth';
oscillator.frequency.value = Freq;
oscillator.start();
gainNode.gain.value = Vol;
var CurX;
var CurY;
document.onmousemove = updatePage;
function updatePage(e) {
CurX = (window.Event) ? e.pageX : event.clientX + (document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft);
CurY = (window.Event) ? e.pageY : event.clientY + (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop);
oscillator.frequency.value = (CurX/WIDTH) * FreqMax;
gainNode.gain.value = (CurY/HEIGHT) * FreqMax;
canvasDraw();
}
</script>
<!DOCTYPE html>
<html>
<body onmousemove="drawe();" onchange="drawe();">
<canvas id="myCanvas" width="500" height="500" style="border:1px">
Your browser does not support the canvas element.
</canvas>
<script>
function drawe(){
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
ctx.moveTo(event.x,event.y);
ctx.lineThickness='100px';
ctx.lineTo(event.x+5,event.y+5);
ctx.stroke();
}
</script>
</body>
</html>