Why shouldn't the music I posted go back more than a couple of 1,000 years? And not only the Sami chants in the first video.
The thing that discerns modern (originally) European music from other music cultures is not harmony but the invention of modulation in harmony.
Harmony is implied in every single note you play through the overtones. Ever tried to sing more than one voice at the same time?
An there is also a theory that polyphonic music developed through the echo and reverb of monophonic music sung in churches. Which might again be an euro-american-Christian-centric view because people attending rituals in stone-age caves would experience echo as well.
Red Rodney Interview
Today, 08:13 AM in The Players