Update app.js

javascript/app.js

@@ -202,6 +202,7 @@ class MidiVisualizer extends HTMLElement{
     }
 
     finishAppendMidiEvent(){
+        this.pause()
         let midiEvents = this.midiEvents.sort((a, b)=>a[1]-b[1])
         let tempo = (60 / 120) * 10 ** 3
         let ms = 0