Once you've identified the surviving primary sources of a work, and the libraries that own them, how do you get to see them? Some sources, of course, are too rare or fragile to be loaned via interlibrary loan. You can travel to the holding libraries. Or, for many early sources, various kinds of reproductions are available.
The Music and Performing Arts Library is home to the Renaissance Music Archive, comprised of roughly 1600 manuscripts on microfilm. The Census-catalogue of manuscript sources of polyphonic music, 1400-1550 (Reference ML169.8 R36 (5 vols)) offers more detail about the works in this collection.
Printed facsimiles of a manuscript can serve as a good surrogate when it is not possible to examine the original manuscript.
"Name given to a genre of book publishing based on photo-mechanical printing techniques that attempts to recreate the appearance of an original handwritten manuscript or printed edition. Facsimile reproductions employ a wide range of photographic methods and materials. The most sophisticated try to be as faithful to the original as possible by replicating its size, colours, paper, binding and, sometimes, physical condition." From the Grove Music Online entry for "Facsimile."
For facsimiles of medieval collections, try subject headings like these:
These published facsimiles are generally available via IShare or interlibrary loan, if UIUC doesn't have them.
In addition to print resources, the Music and Performing Arts Library also has an extensive collection of primary source materials from other research libraries on microfilm. These can include manuscripts and early printed editions.
The Library's online catalog will tell you if what you have found is a microfilm in two ways. First, in the "Notes" field it will say "Microfilm" and describe how many reels. Second, the call number for the item will start with "FILM."
To access microfilms, take the call number to the Music and Performing Arts Library's circulation desk and the item will be paged for you. To view the microfilm, you can use our regular viewer/printer or our digital viewer/scanner.