A virtual library of some 2,700 pieces of sheet music published in California between 1852 and 1900, together with related materials such as a San Francisco publisher's catalog of 1872, programs, songsheets, advertisements, and photographs
Digitized versions of an impressive collection of works published in the United States between 1850 and 1920, from the Duke University library
IN Harmony - Sheet Music from Indiana
A search and discovery system for accessing sheet music from the Indiana University Lilly Library, the Indiana State Library, the Indiana State Museum, and the Indiana Historical Society.
Latin American Choral Music
An ongoing compilation of information about choral music by Latin American composers from 1550 to the present.
A commercial site, but great listing of operas currently being performed internationally. Listings by artist, composer and work. Also a very comprehensive list of recordings of all types of works – a nice information source, with an Italian bent
Public Domain Song Anthology
An open access collection of 348 songs with modern and traditional harmonization. You can download files as individual PDFs, XML and Sibelius files.
Includes both state-related works and a collection of music by women composers. Women's Suffrage in Sheet Music
Rally songs and works by both well-established composers ad ordinary citizens. Contains music both in favor of and against the suffragist movement between 1838 and 1923