index.js

// DETECTING THE CLICK

var numberofdrumbutton=document.querySelectorAll(".drum").length;

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

            makesound(buttoninnerhtml);

            buttonAnimation(buttoninnerhtml);   //Calliong buttonanimation function.

            }); 
        } 
        
// Detecting the Keyboard Press... 

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

    buttonAnimation(event.key);   //Calliong buttonanimation function.
});

// PLAYING FUNCTION MAKESOUND...


  function makesound(key){

    switch (key) {
        case "w":
            var tom1 = new Audio('sounds/tom-1.mp3');
            tom1.play();
            break;
            
        case "a":
            var tom2 = new Audio("sounds/tom-2.mp3");
            tom2.play();
            break;

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

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

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

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

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

        default:
            console.log(buttoninnerhtml);
    }
  }

  //Creating function ButtonAnimation 


  function buttonAnimation(currentKey){

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

    activebutton.classList.add("pressed");

    setTimeout(function(){

        activebutton.classList.remove("pressed");},100);
  }