WorldCat
A vast online catalog citing items owned by thousands of libraries around the world, with information on which libraries own them; includes entries for musical scores and sound recordings; cites journal holdings, but does not provide article access. 
Use this resource to initiate inter-library loan requests for books and scores we do not have. When you find an entry for a specific item you need, click on the ILL link you will find there to launch your request with our inter-library loan department.
Few libraries lend sound recordings due to their fragility. However, it is permissible to request them in case a lender can be found. 
For anyone familiar with OCLC, WorldCat is the OCLC Online Union Catalog.  
This is not a full-text database.
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Please note:  There is also a free version of WorldCat at this URL:
www.worldcat.org
If you use the free WorldCat on a UNT computer, it will include links to our inter-library loan service.
If you enter your ZIP code on the free WorldCat, it will tell you how many miles you would have to travel to the libraries that have the items you want.
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ProQuest Dissertations and Theses (electronic version of the print resource Dissertation Abstracts, which had been published since 1952 with coverage back to 1861)
Bibliographic citations for doctoral dissertations and master's theses in all fields from numerous accredited colleges and universities worldwide, with emphasis on U.S. schools; abstracts provided from 1980 forward; now includes full text of over one million dissertations.
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Academic Search Complete
Database providing full-text journal coverage for thousands of journals in diverse academic disciplines, including social sciences, humanities, education, computer sciences, engineering, language and linguistics, arts & literature, medical sciences, and ethnic studies; links to full text of journals through EbscoHost.
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JStor
Full text of journal articles from a large number of disciplines; its specialty is providing backfiles, that is to say, all of the back issues of many important journals in music and other fields. 
Caution: JStor is very popular. However, since its specialty is backfiles, this means that it may not provide current issues of the journals you need. Thus, do NOT limit yourself solely to it when searching for articles.