index.js

//Detecting Button Press


for (var i = 0; i < document.querySelectorAll(".drum").length; i++) {

  document.querySelectorAll(".drum")[i].addEventListener("click", function () {

    var buttonInnerHTML = this.innerHTML;

    makeSound(buttonInnerHTML);

    buttonAnimation(buttonInnerHTML);

  });

}

// Detecting Keyboard Press

document.addEventListener("keydown", function (event) {

  makeSound(event.key);

  buttonAnimation(event.key);
});

function makeSound(key) {
  switch (key) {
    case "w":
      var crash = new Audio("sounds/crash.mp3")
      crash.play();
      break;

    case "a":
      var kick = new Audio("sounds/bass.wav")
      kick.play();
      break;

    case "s":
      var snare = new Audio("sounds/snare.mp3")
      snare.play();
      break;

    case "d":
      var tom1 = new Audio("sounds/tom-1.mp3")
      tom1.play();
      break;

    case "j":
      var tom2 = new Audio("sounds/tom-2.mp3")
      tom2.play();
      break;

    case "k":
      var tom3 = new Audio("sounds/tom-3.mp3")
      tom3.play();
      break;

    case "l":
      var tom4 = new Audio("sounds/tom-4.mp3")
      tom4.play();
      break;

    default:
      console.log(buttonInnerHTML);

  }

}

function buttonAnimation(currentKey) {

  var activeButton = document.querySelector("." + currentKey);

  activeButton.classList.add("pressed");

  setTimeout(function () {
    activeButton.classList.remove("pressed");
  }, 100);

}