I don't see how to access any pre-installed sounds. In Calendar or Contacts when I try to assign a sound/ringtone, I get "Choose path" and it points to /storage/emulated/0/Ringtones, where I had copied in some sounds of my own. I must have tried to assign custom tones earlier to find out what path it was looking at, then dumped my own files there. But where is the default sound? The chooser won't let me navigate out of /storage/emulated.