index.js

// detecting for mouse click

for (var i = 0; i < document.querySelectorAll(".drum").length; i++) {
  document.querySelectorAll(".drum")[i].addEventListener("click", function() {

    var buttonInnerHtml = this.innerHTML;
    makeSound(buttonInnerHtml);
    makeAnimation(buttonInnerHtml);
  });
}

// detecting for keypress
document.addEventListener("keydown", function(event) {
  makeSound(event.key);
  makeAnimation(event.key);
});

// function to play audio

function makeSound(key) {
  switch (key) {
    case "w":
      var audio = new Audio("sounds/tom-1.mp3");
      audio.play();
      break;
    case "a":
      var audio = new Audio("sounds/tom-2.mp3");
      audio.play();
      break;
    case "s":
      var audio = new Audio("sounds/tom-3.mp3");
      audio.play();
      break;
    case "d":
      var audio = new Audio("sounds/tom-4.mp3");
      audio.play();
      break;
    case "j":
      var audio = new Audio("sounds/crash.mp3");
      audio.play();
      break;
    case "k":
      var audio = new Audio("sounds/kick-bass.mp3");
      audio.play();
      break;
    case "l":
      var audio = new Audio("sounds/snare.mp3");
      audio.play();
      break;

    default:
      console.log(key);
  }
}

// fuction to get animation
function makeAnimation(currentKey) {
  var activeButton = document.querySelector("." + currentKey);
  activeButton.classList.add("pressed");
  setTimeout(function() {
    activeButton.classList.remove("pressed")
  }, 100);

}