"half as long gives the octave"

You're right, s&r, I made a mistake. I just measured it on my dulcimer, and the fifth is 2/3 as long, not half. But I consider my point still valid - we can find the important intervals of the octave, the fifth and the fourth by simple means.

The trouble with music history is that so much of it has never been written down. Not just the very old stuff, but the ordinary stuff of the common people. We will probably never know, for example, what words certain old tunes had before they became hymns. People were poor and illiterate, paper and ink were expensive, and everyone, from rich to poor, had more important things to worry about - like surviving.

That said, I'd like to mention that I saw a documentary about a newly-dicovered painted cave in France. The doc was called "Cave of Forgotten Dreams." In the cave, they found a flute which they date at 30,000 years old or so. An archeologist picked up an exact replica of it and played the tune for "The Star-Spangled Banner" on it.

At one time there probably was a drawing that showed one stick figure playing the flute while another covers its ears and says "That's not even music, it's just noise!" but the drawing has weathered away.