because I don't know how else to describe it. 'It' is polyphonic overtone singing or throat singing, where a performer sings two different notes at the same time and what they can do with the technique is extraordinary. German singer, Anna-Maria Hefele, is an expert in the overtone singing technique from Tuva in Russia and produces eerie and lovely music. Once reserved only for men - it was thought to make women infertile - it is now sung by both men and women. In this video Hefele shows just what it is like.

There are other kinds of throat singing notably in Mongolia where it is a traditional music. I found this video just breathtaking.

You can find out more about overtone singing here.http://en.wikipedia.org/wiki/Tuvan_throat_singing.

Thanks to my friend, Annie, for telling me about this.