QUOTE(kerioboe @ Dec 17 2008, 09:03 AM)

With the proviso that I am a lecturer in a different subject (not music), I suggest you ask a less open-ended question.
You can write a thesis on anything and you need to narrow your topic down before asking anyone else's opinion.
Things I tell my own students:
- It has to be something you are interested enough in to want to spend months (if it's an Honours thesis) years (if it's a PhD thesis) researching.
- It should be something you already know something about. It is all right to explore something completely new but you should do some initial reading/ research before committing yourself; otherwise you may rapidly find that just because it is new to you, doesn't mean that it is easy to find something original to say about it.
- Once you have an idea of the area you are interested in, go and look in your University library and see what previous students have already done in that area. (If it is a PhD thesis then you should be looking internationally to see what has been done).
- Most students choose a topic which is too vast.
- To try and clarify what you want to write about it helps to try and formulate a precise question/hypothesis that your thesis will answer/prove.
Good advice, the important thing is to have a clear, tightly focused question. Once you have settled on a fairly limited area, your tutor may be willing to help you arrive at the final question. My experience (in philosophy) is that students tend to pick far too large a topic. Go for depth, not breadth.