Methodology 1 Find your theme
Particularly to H who asked me how to get start your research.
As I know, you have two ways:
1) Your supervisor suggest you the subject.
2) You find it by yourself.
I often hear from scientist having the case 1. Even in this case you have to find your academic interest by yourself. And I strongly believe that it must match your personal interest. I don't recommande this because I saw a Ph. D Student suffering by this.
Once you start, you have to think about this all they long. You should choose something with which you never get bored (while you will be totally fed up with it one day on your path).
Singer friends often treat singing problems; one opera work with musical analytic approach, utterance issue (how operatic singers make their voice) etc.
As for me, I chose something totally another from singing. In this case, and for all case, you had better to well be prepared all questions before talking about your work : Why this?
This question is trap.
In often case, you should not answer your real personal reason. You should get the answer scientifically.
So if people ask me why kagura? If I answer, because I wanted to be a kagura dancer ever since I saw beautiful kagura dancers at my oncle's shrine, it is totally non sense.
You should find the point which nobody worked yet (but you believe that we need to solve it to advance our works.) I personally think it had better not to think about this too much because we cannot get Olympic Gold medal without any practice. Time solve this.
Conclusion, my friend, all you have to do at first is to find your interest. Nobody can help you this.
You analyse yourself, what brings you pleasure to know, what you do always, etc. You can even pointed out 100 your favorite things and find your tendency.
The musicology covers all field. All are possible....
Oops, it must be too long. After finding your interest. Now you are on next step.
To find your own theme, the Japanese university taught me to check them out at first.
(Later I will rewrite the real name and their references)
1) The New Globe (English)
2) MGG (German)
3) Larousse (French)
Plus for Japanese music researchers,
4) Hogaku hyakka jiten
4) Nihon Ongaku daijiten
These dictionaries gives you the current scientific state and REFERENCES.
Then, you read references. After, I don't know the real number of books, you will get the global idea of the theme.
I recommande you to read as well so-called the dictionary of Nattiez (French). It gives you an idea; how to write.
Also you can picking all references you are interested in by JSTOR (this is kind of google in research).
Hopefully you got little bit idea....! Good luck!