let fft; 

let waveform = []; let bins = 512; let r = 300;

let spectrum = [];

​

function preload() {

  song = loadSound("Veiil.mp3");

}

​

function setup() {

  createCanvas(bins, bins);

  song.play();

  fft = new p5.FFT(0.8, bins);

}

​

function draw() {

  background(220);

  waveform = fft.waveform();

  spectrum = fft.analyze();

  let vol = fft.getEnergy(20, 140);

  // Frequency Domain

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

    let y = map(spectrum[i], 0, 255, 0, height);

    line(i, height, i, height - y);

  }

  // Time Domain

  // for (let i=0; i<waveform.length; i++) {

  //   let y = height/2 + map(waveform[i], -1, 1, -r, r);

  //   ellipse(i, y, 1, 1);

  // }

​

}