diff --git a/app/src/main/java/ohi/andre/consolelauncher/commands/raw/tracks.java b/app/src/main/java/ohi/andre/consolelauncher/commands/raw/tracks.java
index a9a47eac08ca909b128aad89fdd5f9c1576a5461..de58d07945f7eea27e903756a1f3031bfd258945 100755
--- a/app/src/main/java/ohi/andre/consolelauncher/commands/raw/tracks.java
+++ b/app/src/main/java/ohi/andre/consolelauncher/commands/raw/tracks.java
@@ -16,7 +16,11 @@ public class tracks implements CommandAbstraction {
     @Override
     public String exec(ExecInfo info) {
         List<String> names = info.player.getNames();
-        Tuils.addPrefix(names, "  ");
+        if(names == null) {
+            return info.res.getString(R.string.output_musicfoldererror);
+        }
+
+        Tuils.addPrefix(names, Tuils.DOUBLE_SPACE);
         Tuils.insertHeaders(names, false);
         return Tuils.toPlanString(names);
     }
diff --git a/app/src/main/java/ohi/andre/consolelauncher/managers/MusicManager.java b/app/src/main/java/ohi/andre/consolelauncher/managers/MusicManager.java
index 84afcfd6a0b4bab90bd67a5e525700c418432bc6..0872d3c2a22211d4ae8a1874e3b8fe7174573f4c 100755
--- a/app/src/main/java/ohi/andre/consolelauncher/managers/MusicManager.java
+++ b/app/src/main/java/ohi/andre/consolelauncher/managers/MusicManager.java
@@ -19,6 +19,8 @@ import ohi.andre.consolelauncher.tuils.broadcast.HeadsetBroadcast;
 
 public class MusicManager implements OnCompletionListener {
 
+    public static final String[] MUSIC_EXTENSIONS = {".mp3", ".wav", ".ogg", ".flac"};
+
     public static final boolean USE_SCROLL_COMPARE = true;
 
     private File songFolder;
@@ -45,6 +47,7 @@ public class MusicManager implements OnCompletionListener {
         c.registerReceiver(headsetReceiver, new IntentFilter(Intent.ACTION_HEADSET_PLUG));
 
         randomActive = Boolean.parseBoolean(preferencesManager.getValue(PreferencesManager.PLAY_RANDOM));
+
         songFolder = new File(preferencesManager.getValue(PreferencesManager.SONGSFOLDER));
     }
 
@@ -60,14 +63,19 @@ public class MusicManager implements OnCompletionListener {
     //	return the path by complete name
     public String getPath(String name) {
         File file = new File(songFolder, name);
-        if (!file.exists())
+        if (!file.exists()) {
             return null;
+        }
         return file.getAbsolutePath();
     }
 
     //	return names
     public List<String> getNames() {
         List<File> songs = Tuils.getSongsInFolder(songFolder);
+        if(songs == null) {
+            return null;
+        }
+
         List<String> names = new ArrayList<>();
 
         for (File file : songs)