WorldCat is a database of other libraries' catalogs. It's available on our "Databases" page.

WorldCat includes the catalogs of most U.S. college and university libraries, other research libraries, and libraries in some thirty other countries.

Many primary sources (manuscripts, early editions, and reproductions such as reprints, facsimiles, and microfilm) are entered in WorldCat. Once you've identified sources of a work in reference tools like Oxford Music Online, composers'  thematic catalogs, and RISM, you can search it in WorldCat and find out which libraries own a copy.

Search the work in WorldCat like you would in a library catalog. Then look for a link "Libraries worldwide that own item."

Reproductions can often be acquired through interlibrary loan.