Expanding my dissertation topic

My problem here isn't Composition related but I am hoping that some of you guys might be able to help me out. Apologizes for the length of the post.

Next Friday, I have to submit my application forms for which modules I want to do next year. As a final year, I am required to do a main project which is worth more credits than other modules. Options in this area go from a Dissertation to a Composition to an Edition.

Last year I had the plan of doing a 40 credit composition and a 20 credit Tonal Studies - which do those who don't know is a thesis on Stylistic features of a form or style e.g Bach's Choral Works followed by examples composed by yourself in that style. However, the format of the Tonal Studies section has changed and while I could still do it, I wouldn't be as large a project as I wanted to undertake and therefore I am less than inspired to pursue it.

I have decided then to take my basis for my Tonal Studies project - Nocturnes - and develop this instead into a Dissertation on the History and Development from its Origins to Modern day. However, I am unsure whether this topic has enough material in it to be worthy of a 9,000 words. (My Tonal project would have only had to be 4000-5000)

Topics/chapters which spring to mind are Pre-John Field, John Field, Chopin contribution, Post Chopin.

I am checking out Grove for ideas and while I don't actually have to state my topic next Friday, I will have to prove I have the motivation behind me to want to undertake TWO major projects alongside my other modules next year.

So basically, this is a very very long winded way of asking for ways in which I could expand my topic without "jumping the shark".

Maybe expand into the disuse of the term and the musical and social reasons for its relative non-use as a term for current music?

Just grasping at straws.