A primary source is any kind of original work, whether that be a letter from a historical time period, an original piece of art, or original scientific research. Types of primary sources in music may include:
RISM - Répertoire International des Sources Musicales
The RISM database is the world's most comprehensive documentation of music manuscripts and printed editions from the period between 1600 and 1800. It is constantly growing through regular updates. It is an essential tool for anyone doing primary source research in the common practice period.
Here are two online collections of musical works that are in the public domain. NOTE: please pay close attention to the copyright warnings on each piece.
Full, study, piano, and vocal musical scores, of both classic and contemporary pieces.
Subscriptions to these databases are provided by HC Libraries. Some of these databases are music related, while some are more broad in subject, but could help you find other primary sources beyond scores and recordings. For more primary source databases, please see the Library Research Database A-Z list and filter it by primary sources.
Date(s): 1740-1940
Historic magazine and journal articles, including professional, childrens' and womens' magazines.
Date(s): 1756-1963
Historic newspapers from all different U.S. states, hosted by the Library of Congress.
Date(s): 1701-1800
British and American books, pamphlets and broadsides from the 18th century.
Date(s): 1880-2015
American and British magazines about film, music, broadcasting, and theatre, including fan magazines. Includes full issues from publications such as Billboard, The Hollywood Reporter, The Stage, Variety, and many more.
Field collections created by ethnomusicologists and focused on music traditions all around the world.
Date(s): 1789-1914
British and American books, pamphlets and broadsides from the "long" 19th century.
Sometimes when looking for primary resources, it is easier to find them by doing your secondary research first and using citations from those articles to find original source material. For example lets say you would like to write a paper on Clara Schumann's compositional work, but you're not sure which pieces of her's to look at. Try conducting your secondary source research first by searching for articles about Clara Schumann as a composer, and then see what works of hers they reference. Using that articles bibliography or citations page can help you find the original source you'd like to work with.
Below is a video on how to use information gleaned from a citation to find a piece of work. If you are struggling to find something from a citation, please visit the research desk at any of the libraries or make an appointment with a librarian for help!