index.js

// Detecting button press
var totbutton = document.querySelectorAll(".drum").length;

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

function HandleClick() {

    var buttoninnerhtml = this.innerHTML;

    makesound(buttoninnerhtml);

    buttonAnimation(buttoninnerhtml);

    setTimeout(buttoninnerhtml);

}

// Detecting keyboard press

document.addEventListener("keypress", function(event){
makesound(event.key);
buttonAnimation(event.key);
setTimeout(event.key);


});

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/snare.mp3');
            audio.play();
            break;
        case "l":
            var audio = new Audio('sounds/kick-bass.mp3');
            audio.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);
}