Name That Tune!
Try these links:
Themefinder. A collaborative project of the Center for Computer Assisted Research in the Humanities (CCARH) at Stanford University and the Cognitive and Systematic Musicology Laboratory at Ohio State.
Musipedia. Find and identify a tune even if the melody is all you know. You can play it on an on-screen keyboard, whistle it to the computer, or tap in the rhythm on a computer keyboard.
Plainsong melodies and texts. Find information on Gregorian chant and other medieval monody, including sacred songs.
International Sound Recording Code (ISRC). An international standard code for uniquely identifying sound recordings and music video recordings. This database is useful for searching for artists who have recorded a specific title, e.g., "Sheep May Safely Graze."
Hymnary. An index of c. 5,000 hymnals and more than one million published hymns, with scores, media, and information from sources such as Julian's Dictionary of Hymnology, hymnal handbooks, and experts in the field. Includes a melody search.
All-But-Forgotten-Oldies. A database of links to oldies song clips from 1960 to 1975. Offers useful tips for identifying a song or recording you can almost but not quite remember.