let button;

let mic;

let fft;

​

function preload() {

  sample = loadSound("https://cdn.jsdelivr.net/gh/processing/p5.js-website@master/src/data/examples/assets/Damscray_-_Dancing_Tiger_02.mp3"); 

}

​

function toggle() {

  if (sample.isPlaying()) {

    sample.pause(); 

  } else {

    sample.play(); 

  }

}

​

function setup() {

  createCanvas(256, 256);

  button = createButton("Toggle");

  button.mousePressed(toggle);

  mic = new p5.AudioIn();

  mic.start();

  fft = new p5.FFT(0.9, 256);

  //fft.setInput(mic);

}

​

function draw() {

  background(0);

  const spectrum = fft.analyze();

  stroke("red");

  for (let i = 0; i < spectrum.length; i += 1) {

     line(i, height, i, height-spectrum[i]);

  }

}