Which hymn is the oldest known song?

The Hurrian songs are a collection of music inscribed in cuneiform on clay tablets excavated from the ancient Amorite-Canaanite city of Ugarit, a headland in northern Syria, which date to approximately 1400 BC. One of these tablets, which is nearly complete, contains the Hurrian Hymn to Nikkal (also known as the Hurrian cult hymn or "a zaluzi-prayer to the gods," or simply "h.6"), making it the oldest surviving substantially complete work of notated music in the world. While the composers' names of some of the fragmentary pieces are known, h.6 is an anonymous work.