Musiques Traditionelles du Burundi

In Boing Boing Meara O'Reilly writes about "about music that disorients the senses" referring to  'Musiques Traditionelles du Burundi' she states:

I just wrote about the amazing ability of some birds to sing multiple notes at once. This woman's ability to switch rapidly between her head and chest voice is totally daring anyone to say humans couldn't defy all odds and learn to do it too: Akazehe par une jeune filleThe liner notes for these songs say that this woman is using her lips as a reed. If you listen carefully, you can hear the switch over to her normal voice. It's a traditional kind of song for mourning...