Some of you may know this, but for those who don't: The oldest known preserved musical notation is a cult hymn from Ugarit (in today's Syria). It sounds quite different from the other ancient music I've heard (Greek, mostly), but it's remarkably sweet to modern ears! And it's surprising to hear terse harmonics.

Of course, there may well be controversies in the interpretation that I'm unaware of. But it's still fascinating.

http://www.webster.sk.ca/greenwich/EVIDENCE.HTM