The Von Trapp children in the musical "The Sound of Music" didn't know how to sing. So Fraulein Maria taught them how using "one word for every note" in the iconic song "Do-Re-Me." But what the fraulein didn't teach the children was how to sing two notes at once.
German singer Anne-Maria Hefele has mastered the technique known as polyphoneic overtone singing and her stunning video of the unusual talent has received more than 1 million views after being posted just last week (Note: the folks at io9 recommend putting in headphones to listen so you can catch all the nuances of the unique sound):
As the Reddit thread where the video was posted a couple of days ago said, the sound "almost doesn't sound real, and this amount of vocal control is insane."
Another singer, Alexander Glenfield, demonstrated the seven different styles of overtone singing — and he offers lessons as well:
In a blog post about overtone sing, Glenfield wrote "overtone singing IS a perfect example of the creation equation. We have what APPEARS to be one note PRODUCING more than one note: melody within drone; movement within stasis; music within sound."