var song;

var button;

var amp;

var volhistory = [];

​

function toggleSong() {

  if (song.isPlaying()) {

    song.pause();

  } else {

    song.play();

  }

}

​

function preload() {

  song = loadSound("rnb.mp3");

}

​

function setup() {

  createCanvas(400, 400);

  song.play();

  button = createButton("toggle");

  button.mousePressed(toggleSong);

  amp = new p5.Amplitude();

}

​

function draw() {

  background(0);

  var vol = amp.getLevel();

  console.log(vol);

  volhistory.push(vol);

  stroke(255);

  noFill();

  beginShape();

  for (var i = 0; i < volhistory.length; i++) {

    var y = map(volhistory[i], 0, 1/3, height/2, 0);

    vertex(i, y);

  }

​

endShape()

  if(volhistory.length > width-50){

    volhistory.splice(0,1);

  }

  stroke(255,0,0);

  line(volhistory.length,0, volhistory.length,400)

}

​