diff --git a/01 - JavaScript Drum Kit/index-START.html b/01 - JavaScript Drum Kit/index-START.html
index 4070d32767..1b824ca99b 100644
--- a/01 - JavaScript Drum Kit/index-START.html	
+++ b/01 - JavaScript Drum Kit/index-START.html	
@@ -58,9 +58,27 @@
   <audio data-key="76" src="sounds/tink.wav"></audio>
 
 <script>
+function playSound(e) {
+  const audio = document.querySelector(`audio[data-key="${e.keyCode}"]`);
+  const key = document.querySelector(`.key[data-key="${e.keyCode}"]`);
+  
+  if(!audio) return; // stop the function from running
+  audio.currentTime = 0;
+  audio.play();
+  key.classList.add('playing');
+  }
 
-</script>
+function removeTransition(e) {
+  if (e.propertyName !== 'transform') return; // skip if it's not a transform
+  console.log(e.propertyName);
+  this.classList.remove('playing');
+  }
+
+const keys = document.querySelectorAll('.key');
+keys.forEach(key => key.addEventListener('transitionend', removeTransition));
+window.addEventListener('keydown', playSound);
 
+</script>
 
 </body>
 </html>