diff --git a/voicegardens/static/voicegardens.js b/voicegardens/static/voicegardens.js
index dff5015..9f2d93b 100644
--- a/voicegardens/static/voicegardens.js
+++ b/voicegardens/static/voicegardens.js
@@ -200,7 +200,7 @@ class GeneratedShape {
     var duration = 0.8;
     var time = 0;
     var velocity = 0.5;
-    var index = random(0, notes.length + 1);
+    var index = floor(random(0, notes.length));
     this.synth.play(notes[index], velocity, time, duration);
   }