text: var numberOfButtons = document.querySelectorAll(".drum").length;
  
  
  //detecting button
  
  for (var i= 0; i<numberOfButtons; i++){
  
    document.querySelectorAll(".drum")[i].addEventListener("click", handleclick);
  
    function handleclick(){
  
      var buttonInnerHTML = this.innerHTML;
  
      makeSound(buttonInnerHTML);
  
      keyanimation(buttonInnerHTML);
    }
  }
  
  
  //detecting keyborad press
  
  document.addEventListener("keypress", function(event){
  
    makeSound(event.key);
  
    keyanimation(event.key);
  
  
  });
  
  function makeSound(key) {
    
    switch (key) {
        case "w":
          var crash = new Audio("sounds/crash.mp3");
          crash.play();
          break;
  
        case "a":
          var kickbass = new Audio("sounds/kick-bass.mp3");
          kickbass.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);
          break;
    
    }
  }
  
  function keyanimation(currentkey){
  
    var activeButton = document.querySelector("." + currentkey);
  
    activeButton.classList.add("pressed");
  
    setTimeout(function () {
  
      activeButton.classList.remove("pressed");
    }, 100);
  
  }