The easiest way to locate dissertations is to search Proquest Dissertations Database.
You can also locate dissertations in online catalogs and within some digital repositories of universities.
Often, dissertations can be located in the music database RILM.
If you come across a citation for a dissertation, try searching Proquest Dissertations Database, then RILM, then Worldcat. If you still cannot find a dissertation, contact your librarian for assistance.