Microsoft® Encarta® 2009 offers the following definitions which I cannot untangle.
Contents, plural noun
- the subject matter of a document or publication I revealed the contents of the letter
Content, noun (plural con·tents)
subject matter: the various issues, topics, or questions dealt with in speech, discussion, or a piece of writing a speech that was highly emotive in both tone and content
the meaning or message contained in a creative work, as distinct from its appearance, form, or style.