DESCRIPTION:
The Ainu is a minority people who has lived in the northern region of Japan.
They sang traditional Upopo of Ainu People of the regions Obihiro, Urakawa, and Chitose and so on.
Charanke Festival 2011, Yakushiji Temple Tokyo, October 29th 2011

Upopo:
The most conspicous feature of upopo is its poly-phonic rendition. Upopo is sang like a troll - following the principle of imitation with a time lag -, sitting round and tapping the rhythm on the lid of a table with the hand.
After a while the sound becomes chatic. This may explain the use of the word upopo(boiling pot or birds chirping).