var button;

var amp;

​

// function preload(){

//   song= loadSound("sound2.mp3");

// }

​

function setup() {

  createCanvas(400, 400);

  background(50);

  song= loadSound("songex.mp3",loaded);

  amp=new p5.Amplitude();

}

function loaded(){

button=createButton("play");     button.mousePressed(togglePlaying);

}

​

function draw(){

  background(50);

  var vol=amp.getLevel();

  var diam=map(vol,0,0.3,10,200);

  fill(255,0,255);

  ellipse(width/2,height/2,diam,diam);

}

function togglePlaying(){

  if(!song.isPlaying()){

  song.play();

  song.setVolume(0.3);

  button.html("stop");

}else {

  song.pause();

  button.html("play");

}

}