Remember that most if not all recorded sound is under copyright and not in the public domain, only the words of the music themselves are in the public domain.
Public Domain Music Directories
- Wikimedia Commons – tons of free stuff here
- Creative Commons – lots of resources
- Internet Archive – video, sound, pictures
- PD info – Public Domain Music and Royalty Free Music
Public Domain Sheet Music
- 19th-Century American Sheet Music Digitization
- 19th-Century California Sheet Music
- African American Sheet Music (1850-1920)
- Ceolas: Celtic music
- Historic American Sheet Music Project (1850-1920)
- Hollis from 1560-c1830.
- The Lester S. Levy Sheet Music Collection
- Music for the Nation: American Sheet Music, 1870-1885
Public Domain Research Sites
- The Library of Congress offers extensive music reference.
- Digital Tradition Folk Music
- The Ballad Index Web Site Folk Music
Public Domain Songs in MIDI
- PD Music. several hundred public domain songs sequenced, incredibly well done!
- The Cyber Hymnal web site has lyrics and midi files for hundreds of hymns.
Royalty Free Sound Effects
- Sound Snap This site offers lots of professional quality Royalty Free Sound Effects at No Charge.
Royalty Free Music
- 2b Royalty Free Music Library Royalty free music and sound effects
- Hollywood Edge An Audio Source for studio films, expensive sound effects and such, many free offerings, top quality.
- Music2Hues has a wonderful royalty free music library
- Royalty Free Music Library A very large selection of royalty free recordings
- RoyaltyFreeMusic.com Over 70 albums with 700 tracks
- Sound Ideas An Audio Source for studio films, expensive sound effects and such, many free offerings, top quality.
- Dano Songs