How To Sing Two Notes At The Same Time

Here is a young lady singing two notes at once. Something of a rare talent which the internet hasn’t seen a great deal of.
Anna-Maria Hefele is an overtone singer and voice artist. She plays nyckelharpa, harp & other instruments.
In 2014 she graduated as Bachelor of Arts in Elemental Music & Dance Education with classical singing as her main subject from the Carl Orff Institute, Mozarteum University Salzburg
She started with overtone singing in 2005 and has written compositions for polyphonic solo voice since 2006. In 2006 she started building music instruments for her own use e.g. didgeridoo, wooden alpine flute (mit 6 holes), occarina, Bohemian folk harp.
A genuine talent here and something a little terrifying about the whole thing – but enjoyable all the same, right?