Here's the sheet music for the oldest song in the world:
The song was discovered in the ancient Syrian city if Ugarit in the early Fifties, and then deciphered by Professor Anne Draffkorn Kilmer. The tablets containing the notation were about 3400 years old, and contained cuneiform signs in the hurrian language that provided musical notation of a complete cult hymn. It's thought to be the oldest preserved song with notation in the world, and predates the next earliest example of harmony by 1,400 years.
n 1972, Kilmer, who is professor of Assyriology, University of California, and a curator at the Lowie Museum of Anthropology at Berkeley, developed an interpretation of the song based on her study of the notation. She wrote a book (Sounds From Silence) about her quest, which comes with a CD recording of the song: Link
You can listen to it yourself. Here is a midi version: download the oldest song in the world
From a February, 1988 issue of Archeologia Musicalis:
The top parts were the words and the bottom half instructions for playing the music. The song, it turns out, is in the equivalent of the diatonic "major" ("do, re, mi") scale. In addition, as Kilmer points out: "We are able to match the number of syllables in the text of the song with the number of notes indicated by the musical notations." This approach produces harmonies rather than a melody of single notes. The chances the number of syllables would match the notation numbers without intention are astronomical.
Evidence both the 7-note diatonic scale as well as harmony existed 3,400 years ago flies in the face of most musicologist's views that ancient harmony was virtually non-existent (or even impossible) and the scale only about as old as the Ancient Greeks, 2000 years ago. Said Kilmer's colleague Richard Crocker: "This has revolutionized the whole concept of the origin of western music."