Libraries with song indexes include the University of Tennessee at Knoxville Library, the Libraries of the University of Washington, the California Library Systems Cooperative and the Los Angeles Public Library System. The Oberlin College Libraries host an index of folk songs. Some song indexes, such as that of the Choral Public Domain Library, let users search a downloadable database of sheet music.
Song indexes list songs by title or other reference information. Researchers, musicians and other interested parties can use an index to track down a specific title, recording or piece of music. The University of Washington Music Library and Listening Center hosts a song index of popular songs searchable by title keyword. Search results show song titles matching any keywords used, the publication in which to find the song and the call number of that publication.
The Folk Song Index hosted by Oberlin College Libraries is a joint effort between Sing Out!, a non-profit music education group, and Oberlin College. The database is searchable by song title, publication containing the song of interest and more specific keywords such as the first line of the song's chorus or verse. Search results show the song's title, the first line of the verse, the composer's name and, if available, the first line of the chorus.