         }
         
         if holdMode {
-            if keysHeld.contains(key) {
+            if midiNotesHeld.contains(midiNoteFromTag(key.tag)) {
                 turnOffKey(key)
                 return
             }

        }
    }
    
    
    // About App
    @IBAction func audioKitHomepage(sender: UIButton) {
        if let url = NSURL(string: "http://audiokit.io") {

    }
    
    func toggleKeyHeld(key: UIButton) {
        if let i = midiNotesHeld.indexOf(midiNoteFromTag(key.tag)) {
                midiNotesHeld.removeAtIndex(i)
        } else {
            midiNotesHeld.append(midiNoteFromTag(key.tag))
        }
    }
    
    func toggleMonoKeyHeld(key: UIButton) {
        if midiNotesHeld.contains(midiNoteFromTag(key.tag)) {
            midiNotesHeld.removeAll()
            midiNotesHeld.append(midiNoteFromTag(key.tag))
        } else {
            midiNotesHeld.removeAll()
        }
    }
