createCanvas(400, 400);

}

​

function draw(){

    background(245)

    stroke(0, 109, 203)

​

    //populate volHistory

    if(song.isPlaying()){

        var vol = amp.getLevel()

        volHistory.push(vol)

    }

​

    //iterate through volHistory and draw

  fill(0, 109, 203)

  var barWidth = 2;

  var offsetWidth = 5;

  var offset = 5;

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

        var barHeight = map(volHistory[i], 0, 1, 1, height)

        rect(i + offset, (height/2.0) - (barHeight/2.0), barWidth, barHeight);

        offset += offsetWidth;

    }

​

    //moves wavelength 1 index at a time and account for bar width and offset width

    if(volHistory.length * (offsetWidth + barWidth) > width - 10){

        volHistory.splice(0, 1)

    }

​

    //draw vertical line

    stroke(250, 30, 100)

    line(volHistory.length + offset, 0, volHistory.length + offset, height)

}