This bug has been opened here: https://bugzilla.ubuntu.com/4508

"THe main window is useful to see you videos, but when I read MP3 songs, I don't
want to see that window, I just want to see the basic controls/button, to reduce
the size of the UI and make it look cleaner.
But I can't do it. I disabled the visual effects, clicked on 'resize windows
automatically", but nothing, it still displays the main window. If I try to
reduce it using the mouse, it doesn't work either. The smallest I can shrink it
to is to be seen on the screen capture attached.
Totem ought to hide the main windows if the media it's playgin is music not
video, and if visual effect are disabled, no ?
That's what I expected it to do anyway.... but doesn't work :o(é