Apparently this is HELLA HARD to do. I believe it. An oldie but a goodie.
9th March, 2017 - Polyphonic vocalist does the impossible
by Anna-Maria Hefele | http://www.anna-maria-hefele.com/ https://www.facebook.com/amoberton sign up for my newsletter! http://bit.ly/1TdxQty ⇊⇊⇊ more info: ⇊⇊⇊ my ensembles! http://www.supersonus.eu - http://www.ladyandcat.com overtone singing is a voice technique where it seems like one person sings two notes at the same time. You can sing the overtone scale on one fundamental.