Title:
"Set lyrics automatically" cannot be terminated

Text from bug tracker:
A problem can occur when I right-click on a file and select "Set lyrics
automatically". If I perform that action on an obscure artist whose lyrics
will not be found, the "Performing changes..." window appears and never
goes away. I've literally waited for ten minutes on occasion; the lyrics
are never found, and the window never closes. Since that window makes it
impossible to do anything with aTunes, when this happens, I must forcefully
kill the program.
This would not be such a problem if there was an actual way to close the
"Performing changes..." window before it finishes its task. The window has
no cancel button; it _does_ have an 'X' button, but it does not actually
do anything.
While less frequent, I've also had perpetual "Performing changes..."
windows occur while trying to do other tag-related tasks.
This could be fixed either by tracking down why the "Performing changes..."
window on occasion does not terminate or by adding a way for the user to
close the window.