Fixed small error in music player track selection

public/js/music.js

@@ -43,6 +43,9 @@ function changeAudioSources(trackElem) {
 
   // loop through the audio player source elements
   playerSources.each(function(source) {
+    // jQuery-ize the element
+    source = $(source);
+
     if (source.attr('type') == 'audio/ogg') {
       // OGG source file
       source.attr('src', audioFilePath + '.ogg');