I found a couple of examples of post graduate studies on Zappa that may inspire anyone who may be interested in studying something along similar lines (see my earlier post). They are entitled
A Study in the Instrumental Music of Frank Zappa
Frank Zappa’s Orchestral Works: Art Music or Bogus Pomp
Creative Control: Morton Feldman, Lars von Trier, and Frank Zappa (with original composition)
Musical Meaning in Frank Zappa’s The Blue Light and Galoot Update
If anyone has heard of any others – please let me know.

I would add:
An Original Composition, Symphony No. 1, Pollock and an Analysis of the Evolution of Frank Zappa’s “Be-Bop Tango”
http://etd.lsu.edu/docs/available/etd-12092003-121423/
Not a dissertation, but an interesting research site is:
Zappa Research
http://researchblog.andremount.net/
And of course a dissertation by Ulrik Volgsten “Music, Mind and the Serious Zappa”.
http://www.arf.ru/Biblio/mmser.html
I’m looking for this item many years without any success. Probably you can find it in some big library, but never in eBay, abebooks etc.