Messy messing with the browser's AudioContext capabilities...

AudioContext.html

<script type="application/javascript">

	// create web audio api context
	var audioCtx = new (window.AudioContext || window.webkitAudioContext)();

	// create Oscillator and gain node



	// connect oscillator to gain node to speakers
	var initialFreq = 400;
	var initialVol = 0.001;

	// set options for the oscillator

	var oscillator = audioCtx.createOscillator();
	var gainNode = audioCtx.createGain();	
	oscillator.type = 'sine';
	oscillator.frequency.value = initialFreq; // value in hertz
	oscillator.detune.value = 50; // value in cents
	gainNode.gain.value = initialVol;
	oscillator.frequency.value = 2500;
	gainNode.gain.value        = .01;
	oscillator.connect(gainNode);
	gainNode.connect(audioCtx.destination);	
	oscillator.start(0);	

	
	function rand(a, z){
		return Math.floor((Math.random() * z) + a);
	}
	
	function oneIn(x){
		return Math.floor(Math.random() * 100) % x == 0;
	}


	var last = 1;
	var types = ['sine','sine','square','sawtooth'];
	var prev = 800;
	
	function setFreq()
	{
		oscillator.type = types[rand(0, (types.length-1))];	
		gainNode.gain.value = .02;
		
		var anew = rand(prev, 800);
		if(anew < 200) anew = 200;
		if(anew > 800) anew = 800;
		oscillator.frequency.value = anew / last;

		prev = anew;
		
		if(oneIn(6)){
			oscillator2.frequency.value = oscillator.frequency.value / rand(3, 8);//  your code here
			oscillator.type     = 'triangle';
			gainNode.gain.value = .008;
			oscillator.detune.value = 150;
		}else{
			oscillator.frequency.value = oscillator2.frequency.value / rand(1, 4);//  your code here
		}
		
		myLoop();
		setTimeout(setFreq, rand(1500, 3500));
	}
	
	function myLoop (type) {           //  create a loop function
		oscillator.detune.value = last * 25;
		if(type == 'pos'){
			gainNode.gain.value = gainNode.gain.value + .0002; 
			last = last + .25;
			var newval = oscillator.frequency.value / last;	
		}else{
			gainNode.gain.value = gainNode.gain.value - .0005; 
			last = last - .5;
			var newval = oscillator.frequency.value * .5;
		}
		if(newval < 200) newval = 200;
		if(newval > 1000) newval = 1000;
		oscillator.frequency.value = newval;
		if(last >= 12) last = 1;
		if(last <= 1 ){
			last = 12;
			oscillator.frequency.value * prev;
		}
		setTimeout(function () {				 
			if (gainNode.gain.value < -.035) { 
				myLoop('pos'); 
			}else if (gainNode.gain.value > .035){
				myLoop('neg'); 
			}else{
				myLoop('neg');	
			}//  ..  setTimeout()
		}, rand(100,400))
	}	

	
	var oscillator2 = audioCtx.createOscillator();
	var gainNode2 = audioCtx.createGain();
	oscillator2.type = 'square';
	oscillator2.frequency.value = initialFreq; // value in hertz
	oscillator2.detune.value = 100; // value in cents
	oscillator2.frequency.value = 2500;
	gainNode2.gain.value        = .01;
  	oscillator2.connect(gainNode2);
	gainNode2.connect(audioCtx.destination);
	oscillator2.start(0);	
	
	var prev2 = 400;
	function setFreq2(){
		oscillator2.detune.value = last * 50;
		oscillator2.type = types[rand(0, (types.length-1))];	
		gainNode2.gain.value = rand(.001,.02);
		var anew2 =  rand(200, 400);
		oscillator2.frequency.value = anew2;
		if(oneIn(4)) oscillator2.frequency.value = oscillator.frequency.value / 2;//  your code here
		else myLoop2();
		
		prev2 = anew2;
		
		setTimeout(setFreq2, rand(5000, 10000));
	}
	
	function myLoop2 (type) {           //  create a loop function
		if(type == 'neg'){
			gainNode2.gain.value = gainNode2.gain.value - .0001; 
			last = last - 2;
			var newval = oscillator.frequency.value / last;
			oscillator2.frequency.value = oscillator2.frequency.value / last;
		}else{
			gainNode2.gain.value = gainNode2.gain.value + .0001; 
			last = last + 2;
			var newval = oscillator.frequency.value / last;
		}		
		if(newval > 400) newval = 400;
		if(newval < 100) newval = 100;
		oscillator2.frequency.value = newval;
		
		setTimeout(function () {
			if (gainNode2.gain.value > .03) { 
				myLoop2('neg');
			}else if (gainNode2.gain.value < -.03){
				myLoop2('pos'); 
			}else{
				myLoop2('neg');	
			}
		}, rand(10,100))
	}		
	

	var oscillator3 = audioCtx.createOscillator();
	var gainNode3 = audioCtx.createGain();
	oscillator3.type = 'sine';
	oscillator3.frequency.value = initialFreq; // value in hertz
	oscillator3.detune.value = 100; // value in cents
	oscillator3.frequency.value = 2500;
	gainNode3.gain.value        = .01;
  	oscillator3.connect(gainNode3);
	gainNode3.connect(audioCtx.destination);
	oscillator3.start(0);	
	
	function setFreq3(){
		//if(oneIn(2)){
			if(oscillator2.frequency.value / 2 < 100){
				oscillator3.frequency.value = oscillator2.frequency.value * rand(2,3);//  your code here
			}else{
				oscillator3.frequency.value = oscillator.frequency.value / rand(2,5);//  your code here
			}
		//}
		setTimeout(setFreq3, rand(500, 1270));
	}
	
	setFreq3();
	setFreq2();
	setFreq();

</script>

<h1>Hello World!</h1>