Sheet Music in the Public Domain
Art Song Central!
California Sheet Music Project
Charles Templeton Sheet Music Collection
Civil War Sheet Music Collection
Edison sheet music collection
Florida Sheet Music Collections
Free Sheet Music Public Domain
Historic American Sheet Music – Duke Libraries
Historic Sheet Music Collection, 1800-1922
IN Harmony: Sheet Music from Indiana
Iowa Digital Library Historic Sheet Music
Keffer Collection of Sheet Music
Kreusch-Sheet-Music.net
LSU Music Resources Sheet Music Collection
Music for the Nation: American Sheet Music, ca. 1870-1885
Sheet Music Archive
Sheet Music Consortium
The Danish National Digital Sheet Music Archive
The Lester S. Levy Sheet Music Collection
The Mutopia Project (CC BY-SA 3.0) – offers sheet music editions of classical music for free download. These are based on editions in the public domain, and include works by Bach, Beethoven, Chopin, Handel, Mozart, and many others. License details
They’re wearing ’em higher in Hawaii: Mohr, Halsey K., composer CC0
UNC-Chapel Hill Libraries
UO Libraries Historic Sheet Music Collection
Yiddish Sheet Music