One of the requirements of your paper is to 'dig deep' in seeking secondary sources. When you find sources that are of interest to you in the footnotes and bibliographies of your research/readings, you will need to check the WU Catalog, Mobius, or perhaps WorldCat to find these sources. Below are direct links to these catalogs. (You can get to Mobius from the WU Catalog.)
As starting points I have also included some common subject headings for Greek and Roman music, and the initial sources of information that Prof. Moore had you explore in January.