diff --git a/01 - JavaScript Drum Kit/index-START.html b/01 - JavaScript Drum Kit/index-START.html
index 4070d32767..c7df3437ef 100644
--- a/01 - JavaScript Drum Kit/index-START.html
+++ b/01 - JavaScript Drum Kit/index-START.html
@@ -58,9 +58,23 @@
-
+ function removeTransition(e) {
+ if (e.propertyName !== 'transform') return;
+ this.classList.remove('playing');
+ }
+ const keys = document.querySelectorAll('.key');
+ window.addEventListener('keydown', playAudio);
+ keys.forEach(key => key.addEventListener('transitionend', removeTransition));
+