How do I fix the buttons, I want the music to not play at first but then when you click the buttons it plays its respective music that is attached to the buttons?

p5.js Coding Questions
1 
let buttons = ["Its Yours", "Dance On My Skin", "East of Eden", "Loathe"];
let img;
let font;
let fft;
let freqs = ["bass", "lowMid", "mid", "highMid", "treble"];
let song1;
let song2;
let song3;
let song4;

function preload() {
  song1 = loadSound("songs/itsyours.mp3");
  song2 = loadSound("songs/danceonmyskin.mp3");
  song3 = loadSound("songs/eastofeden.mp3");
  song4 = loadSound("songs/loathe.mp3");
  img = loadImage("images/coldsun.jpg");
  font = loadFont("font/Akshar-VariableFont_wght.ttf");
}

function setup() {
  createCanvas(1000, 800);
  textFont(font);

  noStroke();
  let button1 = createButton(buttons[0]);
  button1.position(0, 550);
  button1.size(width / 4, 100);
  button1.style("textFont", "font");
  button1.style("font-size", "25px");
  button1.mousePressed(playSong1());
  let button2 = createButton(buttons[1]);
  button2.position(250, 550);
  button2.size(width / 4, 100);
  button2.style("textFont", "font");
  button2.style("font-size", "25px");
  button2.mousePressed(playSong2());
  let button3 = createButton(buttons[2]);
  button3.position(500, 550);
  button3.size(width / 4, 100);
  button3.style("textFont", "font");
  button3.style("font-size", "25px");
  button3.mousePressed(playSong3());
  let button4 = createButton(buttons[3]);
  button4.position(750, 550);
  button4.size(width / 4, 100);
  button4.style("textFont", "font");
  button4.style("font-size", "25px");
  button4.mousePressed(playSong4());
  fft = new p5.FFT();
}

function draw() {
  background(28);
  tint(150);
  image(img, width / 4, 0, 500, 500);

  let spacing = width / 10;
  let margin = spacing / 5;
  let spectrum = fft.analyze();

  for (let i = 0; i < 10; i = i + 1) {
    let x = margin + spacing * i;
    for (let j = 0; j < 5; j = j + 1) {
      let y = margin + spacing * j;

      let idx = i * j;
      let amp = map(idx, 0, 59, 0, 4);
      noStroke();
      let energy = fft.getEnergy(freqs[floor(amp)]);
      let w = map(energy, 0, 255, 30, 80);
      let z = 255 - energy;
      fill(255, z, z);
      square(x, y, w, 5);
    }
  }
}

function playSong1() {
  song1.play();
  song2.stop();
  song3.stop();
  song4.stop();
}

function playSong2() {
  song2.play();
  song1.stop();
  song3.stop();
  song4.stop();
}

function playSong3() {
  song3.play();
  song2.stop();
  song1.stop();
  song4.stop();
}

function playSong4() {
  song4.play();
  song2.stop();
  song3.stop();
  song1.stop();
}

function keyTyped() {
  if (key == " ") {
    song1.stop();
    song2.stop();
    song3.stop();
    song4.stop();
  }
}